Author name code: korendyke ADS astronomy entries on 2022-09-14 author:"Korendyke, Clarence M." ------------------------------------------------------------------------ Title: The CCOR-1 Compact Coronagraph: Description and Ground Calibration Results Authors: Thernisien, Arnaud; Carter, Michael; Chua, Damien; Korendyke, Clarence; Socker, Dennis; Babich, Timothy; Baugh, Rebecca; Bonafede, Jo; Boyer, Darrell; Brown, Samuel; Corsi, Keith; Cremerius, Luke; Crippa, Cameron; Davis, Joseph; Gardner, Larry; Clifford, Greg; Hohl, Bruce; Hagood, Robert; Koehler, Matthew; Hunt, Tonia; Kuroda, Natsuha; Lanagan, Andrew; Lynch, Brian; Ogindo, Moses; Noya, Mario; Pellak, Kenneth; Podgurski, Robert; Bordlemay-Padilla, Yadira; Rich, Nathan; Silver, Daniel; Simmons, Jeff; Smith, Linda; Spitzak, John; Tanner, Steven; Uhl, Andrew; Verzosa, Julius; Wiggins, Grayson; Wilson, Courtni; Zurcher, Dallas Bibcode: 2021AGUFMSH43B..08T Altcode: The Compact Coronagraph (CCOR) on the Geostationary Operational Environmental Satellite, GOES-U series, will be one of the cornerstone instruments for space weather forecasting for the National Oceanic and Atmospheric Administration (NOAA), after the scheduled GOES-U spacecraft launch in 2024. The CCOR instrument will monitor the solar corona and detect coronal mass ejections (CMEs) that are directed towards Earth for at least 5 years of GOES-U operations. This presentation describes the CCOR instrument, its planned operations in the GOES-U geosynchronous orbit, and the instrument performance based on ground test measurements and calibration. The Office of Projects Planning and Analysis (OPPA) at NOAA funded the Naval Research Laboratory to develop, build and test the CCOR instrument. Title: The Solar-C (EUVST) mission: the latest status Authors: Shimizu, Toshifumi; Imada, Shinsuke; Kawate, Tomoko; Suematsu, Yoshinori; Hara, Hirohisa; Tsuzuki, Toshihiro; Katsukawa, Yukio; Kubo, Masahito; Ishikawa, Ryoko; Watanabe, Tetsuya; Toriumi, Shin; Ichimoto, Kiyoshi; Nagata, Shin'ichi; Hasegawa, Takahiro; Yokoyama, Takaaki; Watanabe, Kyoko; Tsuno, Katsuhiko; Korendyke, Clarence M.; Warren, Harry; De Pontieu, Bart; Boerner, Paul; Solanki, Sami K.; Teriaca, Luca; Schuehle, Udo; Matthews, Sarah; Long, David; Thomas, William; Hancock, Barry; Reid, Hamish; Fludra, Andrzej; Auchère, Frederic; Andretta, Vincenzo; Naletto, Giampiero; Poletto, Luca; Harra, Louise Bibcode: 2020SPIE11444E..0NS Altcode: Solar-C (EUVST) is the next Japanese solar physics mission to be developed with significant contributions from US and European countries. The mission carries an EUV imaging spectrometer with slit-jaw imaging system called EUVST (EUV High-Throughput Spectroscopic Telescope) as the mission payload, to take a fundamental step towards answering how the plasma universe is created and evolves and how the Sun influences the Earth and other planets in our solar system. In April 2020, ISAS (Institute of Space and Astronautical Science) of JAXA (Japan Aerospace Exploration Agency) has made the final down-selection for this mission as the 4th in the series of competitively chosen M-class mission to be launched with an Epsilon launch vehicle in mid 2020s. NASA (National Aeronautics and Space Administration) has selected this mission concept for Phase A concept study in September 2019 and is in the process leading to final selection. For European countries, the team has (or is in the process of confirming) confirmed endorsement for hardware contributions to the EUVST from the national agencies. A recent update to the mission instrumentation is to add a UV spectral irradiance monitor capability for EUVST calibration and scientific purpose. This presentation provides the latest status of the mission with an overall description of the mission concept emphasizing on key roles of the mission in heliophysics research from mid 2020s. Title: A sensitivity analysis of the updated optical design for EUVST on the Solar-C mission Authors: Kawate, Tomoko; Tsuzuki, Toshihiro; Shimizu, Toshifumi; Imada, Shinsuke; Katsukawa, Yukio; Hara, Hirohisa; Suematsu, Yoshinori; Ichimoto, Kiyoshi; Hattori, Tomoya; Narasaki, Shota; Warren, Harry P.; Teriaca, Luca; Korendyke, Clarence M.; Brown, Charles M.; Auchere, Frederic Bibcode: 2020SPIE11444E..3JK Altcode: The EUV high-throughput spectroscopic telescope (EUVST) onboard the Solar-C mission has the high spatial (0.4'') resolution over a wide wavelength range in the vacuum ultraviolet. To achieve high spatial resolution under a design constraint given by the JAXA Epsilon launch vehicle, we further update the optical design to secure margins needed to realize 0.4'' spatial resolution over a field of view of 100''×100''. To estimate the error budgets of spatial and spectral resolutions due to installation and fabrication errors, we perform a sensitivity analysis for the position and orientation of each optical element and for the grating parameters by ray tracing with the Zemax software. We obtain point spread functions (PSF) for rays from 9 fields and at 9 wavelengths on each detector by changing each parameter slightly. A full width at half maximum (FWHM) of the PSF is derived at each field and wavelength position as a function of the perturbation of each optical parameter. Assuming a mount system of each optical element and an error of each optical parameter, we estimate spatial and spectral resolutions by taking installation and fabrication errors into account. The results of the sensitivity analysis suggest that budgets of the total of optical design and the assembly errors account for 15% and 5.8% of our budgets of the spatial resolution in the long wavelength and short wavelength bands, respectively. On the other hand, the grating fabrication errors give a large degradation of spatial and spectral resolutions, and investigations of compensators are needed to relax the fabrication tolerance of the grating surface parameters. Title: The Solar Orbiter Heliospheric Imager (SoloHI) Authors: Howard, R. A.; Vourlidas, A.; Colaninno, R. C.; Korendyke, C. M.; Plunkett, S. P.; Carter, M. T.; Wang, D.; Rich, N.; Lynch, S.; Thurn, A.; Socker, D. G.; Thernisien, A. F.; Chua, D.; Linton, M. G.; Koss, S.; Tun-Beltran, S.; Dennison, H.; Stenborg, G.; McMullin, D. R.; Hunt, T.; Baugh, R.; Clifford, G.; Keller, D.; Janesick, J. R.; Tower, J.; Grygon, M.; Farkas, R.; Hagood, R.; Eisenhauer, K.; Uhl, A.; Yerushalmi, S.; Smith, L.; Liewer, P. C.; Velli, M. C.; Linker, J.; Bothmer, V.; Rochus, P.; Halain, J. -P.; Lamy, P. L.; Auchère, F.; Harrison, R. A.; Rouillard, A.; Patsourakos, S.; St. Cyr, O. C.; Gilbert, H.; Maldonado, H.; Mariano, C.; Cerullo, J. Bibcode: 2020A&A...642A..13H Altcode:
Aims: We present the design and pre-launch performance of the Solar Orbiter Heliospheric Imager (SoloHI) which is an instrument prepared for inclusion in the ESA/NASA Solar Orbiter mission, currently scheduled for launch in 2020.
Methods: The goal of this paper is to provide details of the SoloHI instrument concept, design, and pre-flight performance to give the potential user of the data a better understanding of how the observations are collected and the sources that contribute to the signal.
Results: The paper discusses the science objectives, including the SoloHI-specific aspects, before presenting the design concepts, which include the optics, mechanical, thermal, electrical, and ground processing. Finally, a list of planned data products is also presented.
Conclusions: The performance measurements of the various instrument parameters meet or exceed the requirements derived from the mission science objectives. SoloHI is poised to take its place as a vital contributor to the science success of the Solar Orbiter mission. Title: Imaging the Solar Corona From Within Authors: Hess, P.; Howard, R.; Vourlidas, A.; Bothmer, V.; Colaninno, R.; DeForest, C.; Gallagher, B.; Hall, J. R.; Higginson, A.; Korendyke, C.; Kouloumvakos, A.; Lamy, P.; Liewer, P.; Linker, J.; Linton, M.; Penteado, P.; Plunkett, S.; Poirer, N.; Raouafi, N.; Rich, N.; Rochus, P.; Rouillard, A.; Socker, D.; Stenborg, G.; Thernisien, A.; Viall, N. Bibcode: 2020AAS...23514907H Altcode: Parker Solar Probe (PSP), launched, in August 2018 is humanity's first probe of a stellar atmosphere. It will make measurements of the near-Sun plasma from 'within' the outer corona with gradually reduced perihelia from its first perihelia of 35 Rs in 2018-19 to 9.8 Rs in 2025. Here we report the results from the imaging observations of the electron and dust corona, whe PSP was 35-54 Rs from the solar surface, taken by the Wide-field Imager for Solar Probe (WISPR). The spacecraft was near-corotating with the solar corona throughout the observing window, which is an unprecedented situation for any type of coronal imaging. Our initial analysis uncovers a long-hypothesized depletion of the primordial dust orbiting near the Sun, reveals the plasma structure of small-scale ejections, and provides a strict test for validating model predictions of the large-scale configuration of the coronal plasma. Thus, WISPR imaging allows the study of near-Sun dust dynamics as the mission progresses. The high-resolution images of small transients, largely unresolved from 1 AU orbits, unravel the sub-structures of small magnetic flux ropes and show that the Sun continually releases helical magnetic fields in the background wind. Finally, WISPR's observations of the coronal streamer evolution confirm the large-scale topology of the solar corona but they also reveal that, as recently predicted, streamers are composed of yet smaller sub-streamers channeling continual density fluctuations at all visible scales. Title: The Compact Heliospheric Imager (CHI): An R2O Instrument Concept for an L5 Space Weather Mission Authors: Chua, D. H.; Thernisien, A.; Korendyke, C.; Socker, D. G.; Noya, M. Bibcode: 2019AGUFMSH43F3351C Altcode: The payload complements specified for most L5 Lagrange point space weather mission concepts include a white-light coronagraph as the primary means to detect the eruption of coronal mass ejections (CMEs) and to establish their initial trajectory into interplanetary space. The design goal outer field of view for an L5 coronagraph is typically about 25 RSun. Once an Earth-directed CME leaves the L5 coronagraph's outer field of view, it loses track of the event and no information about its trajectory or speed is available to operational heliospheric disturbance propagation codes. Forecasters would be blind until the CME reaches the L1 Lagrange point along the Sun-Earth line, where the in-situ measurements would provide only 30-45 minutes of actionable lead time prior to the CME impact at Earth. Adding a heliospheric imager to the instrument suite of an L5 space weather mission will enhance its ability to continuously track CMEs as they leave the L5 coronagraph field of view, improving CME trajectory determination, CME arrival time estimation, and ultimately the accuracy of geomagnetic storm forecasts. The Compact Heliospheric Imager (CHI) is a dual-telescope instrument concept with 30° fields of view that is an ideal candidate for this role on an L5 space weather mission. CHI will image interplanetary space in white light (500-700 nm) between 4.5°-64.5° elongation from L5. This combined field of view encompasses the entire Sun-Earth line with Earth just inside the outer field of view cut off. CHI's enclosed design allows it to be placed close to other spacecraft components or instruments without those components interfering with CHI's imaging performance. This provides a great deal of flexibility in placement of CHI on a spacecraft since its only requirement is to have an unobstructed field of regard (FOR) in the Sun-facing hemisphere. CHI's compact design and low power requirements make it an ideal instrument candidate for an L5 space weather mission. The CHI concept development is supported by the ONR/NRL Bids and Proposals (B&P) Program. Title: Imaging the Solar Corona from Within: First Results from the Parker Solar Probe Telescope Authors: Howard, R. A.; Vourlidas, A.; Bothmer, V.; Colaninno, R. C.; DeForest, C.; Gallagher, B.; Hall, J. R.; Hess, P.; Higginson, A. K.; Korendyke, C.; Kouloumvakos, A.; Lamy, P.; Liewer, P. C.; Linker, J.; Linton, M.; Penteado, P. F.; Plunkett, S. P.; Poirier, N.; Raouafi, N.; Rich, N.; Rochus, P. L.; Rouillard, A. P.; Socker, D. G.; Stenborg, G.; Thernisien, A.; Viall, N. M. Bibcode: 2019AGUFMSH11A..04H Altcode: Parker Solar Probe (PSP) launched in August 2018 is humanity's first probe of a stellar atmosphere. It will make measurements of the near-Sun plasma from 'within' the outer corona with gradually reduced perihelia from its first perihelia of 35 Rs in 2018-19 to 9.8 Rs in 2025. Here we report the results from the imaging observations of the electron and dust corona, whe PSP was 35-54 Rs from the solar surface, taken by the Wide-field Imager for Solar Probe (WISPR). The spacecraft was near-corotating with the solar corona throughout the observing window, which is an unprecedented situation for any type of coronal imaging. Our initial analysis uncovers a long-hypothesized depletion of the primordial dust orbiting near the Sun, reveals the plasma structure of small-scale ejections, and provides a strict test for validating model predictions of the large-scale configuration of the coronal plasma. Thus, WISPR imaging allows the study of near-Sun dust dynamics as the mission progresses. The high-resolution images of small transients, largely unresolved from 1 AU orbits, unravel the sub-structures of small magnetic flux ropes and show that the Sun continually releases helical magnetic fields in the background wind. Finally, WISPR's observations of the coronal streamer evolution confirm the large-scale topology of the solar corona but they also reveal that, as recently predicted, streamers are composed of yet smaller sub-streamers channeling continual density fluctuations at all visible scales. Title: The Solar Polar Observing Constellation (SPOC) Mission: research and operational monitoring of space weather from polar heliocentric orbits Authors: Berger, T. E.; Bosanac, N.; Smith, T. R.; Duncan, N. A.; Wu, G.; Turner, E.; Hurlburt, N.; Korendyke, C. Bibcode: 2019AGUFMSH43F3352B Altcode: The Sun's polar regions remain largely unobserved and yet understanding and monitoring of the magnetic field, convective flows, and coronal outflow conditions in the solar polar regions are the keys to accurately modeling and forecasting the solar cycle, solar wind conditions, and CME arrival times at Earth. We describe the Solar Polar Observing Constellation (SPOC), a mission to establish continuous high-resolution imaging of solar magnetic field dynamics, high-latitude surface and sub-surface convective flows, and coronal mass ejection tracking from a low-eccentricity polar heliocentric orbit. SPOC will consist of two identical spacecraft, each equipped with a Lockheed Martin Compact Magnetic Imager (CMI, derived from the Solar Dynamics Observatory (SDO) Helioseismic and Magnetic Imager), the Naval Research Laboratory (NRL) Compact Coronagraph (CCOR), and in-situ solar wind and energetic particle instruments. Falcon Heavy launch vehicles will place the SPOC spacecraft into a Jupiter gravitational assist (JGA) heliocentric orbit, achieving an 88-degree ecliptic inclination, with the spacecraft passing over the solar poles within 4 years after launch. Ion engines will subsequently reduce the eccentricity of the orbits to below 0.05 at approximately 0.9 AU within 6 years after launch. Orbital phasing will place the spacecraft over alternate poles to enable continuous monitoring of the polar regions with operational-level redundancy of systems. The inclusion of CCOR will enable visualization and tracking of coronal mass ejections from above (or below) the ecliptic for the first time, greatly enhancing our ability to forecast CME arrival times at Earth and other planets such as Mars. SPOC combines polar region exploration, high-latitude helioseismology and magnetic imaging, and operational space weather monitoring in a single mission. Along with planned missions to the L1 and L5 Lagrangian points in the ecliptic, SPOC will enable an approach to the long-sought goal of continuous full-sphere measurements of the solar magnetic field, solar wind and CME outflow, and energetic particle flux - a goal that cannot be achieved with observations from the ecliptic plane alone. Title: The Solar Orbiter Heliospheric Imager (SoloHI) for the Solar Orbiter Mission: Science and Instrument Status Authors: Vourlidas, A.; Howard, R. A.; Colaninno, R. C.; Korendyke, C.; Thernisien, A.; Linton, M.; Tun Beltran, S.; Liewer, P. C.; Velli, M.; Linker, J.; Bothmer, V.; Rochus, P. L.; Lamy, P. L. Bibcode: 2019AGUFMSH24A..08V Altcode: The SoloHI instrument has completed its development effort and has been integrated onto the Solar Orbiter spacecraft. The mission, scheduled for launch in February 2020, will undergo gravity assist maneuvers around Venus to change both the perihelion distance as well as the plane of the orbit to ultimately achieve a minimum perihelion of 0.28 AU and an orbital inclination of about 35° relative to the ecliptic plane. The remote sensing instruments will operate for three 10-day periods out of the nominal 6-month orbit. SoloHI detects sunlight scattered by free electrons in the corona and solar wind from 5° to 45° elongation in visible wavelengths, providing linkage between solar and solar wind observations. The science investigation focuses mainly on the solar wind, including streamers, small-scale intensity and density fluctuations, jets, and Coronal Mass Ejections (CMEs). SoloHI is very similar to the HI-1 instrument on STEREO/SECCHI but with double the FOV of HI-1. In this paper, we present our preparations for the mission including the instrument status, our science planning strategy, our observing plans for cruise phase, calibrations, early science and our low-latency and science data products

This work has been supported by NASA. Title: Near-Sun observations of an F-corona decrease and K-corona fine structure Authors: Howard, R. A.; Vourlidas, A.; Bothmer, V.; Colaninno, R. C.; DeForest, C. E.; Gallagher, B.; Hall, J. R.; Hess, P.; Higginson, A. K.; Korendyke, C. M.; Kouloumvakos, A.; Lamy, P. L.; Liewer, P. C.; Linker, J.; Linton, M.; Penteado, P.; Plunkett, S. P.; Poirier, N.; Raouafi, N. E.; Rich, N.; Rochus, P.; Rouillard, A. P.; Socker, D. G.; Stenborg, G.; Thernisien, A. F.; Viall, N. M. Bibcode: 2019Natur.576..232H Altcode: Remote observations of the solar photospheric light scattered by electrons (the K-corona) and dust (the F-corona or zodiacal light) have been made from the ground during eclipses1 and from space at distances as small as 0.3 astronomical units2-5 to the Sun. Previous observations6-8 of dust scattering have not confirmed the existence of the theoretically predicted dust-free zone near the Sun9-11. The transient nature of the corona has been well characterized for large events, but questions still remain (for example, about the initiation of the corona12 and the production of solar energetic particles13) and for small events even its structure is uncertain14. Here we report imaging of the solar corona15 during the first two perihelion passes (0.16-0.25 astronomical units) of the Parker Solar Probe spacecraft13, each lasting ten days. The view from these distances is qualitatively similar to the historical views from ground and space, but there are some notable differences. At short elongations, we observe a decrease in the intensity of the F-coronal intensity, which is suggestive of the long-sought dust free zone9-11. We also resolve the fine-scale plasma structure of very small eruptions, which are frequently ejected from the Sun. These take two forms: the frequently observed magnetic flux ropes12,16 and the predicted, but not yet observed, magnetic islands17,18 arising from the tearing-mode instability in the current sheet. Our observations of the coronal streamer evolution confirm the large-scale topology of the solar corona, but also reveal that, as recently predicted19, streamers are composed of yet smaller substreamers channelling continual density fluctuations at all visible scales. Title: Concept study of Solar-C_EUVST optical design Authors: Kawate, Tomoko; Shimizu, Toshifumi; Imada, Shinsuke; Tsuzuki, Toshihiro; Katsukawa, Yukio; Hara, Hirohisa; Suematsu, Yoshinori; Ichimoto, Kiyoshi; Warren, Harry; Teriaca, Luca; Korendyke, Clarence M.; Brown, Charles Bibcode: 2019SPIE11118E..1NK Altcode: The main characteristics of Solar-C_EUVST are the high temporal and high spatial resolutions over a wide temperature coverage. In order to realize the instrument for meeting these scientific requirements under size constraints given by the JAXA Epsilon vehicle, we examined four-dimensional optical parameter space of possible solutions of geometrical optical parameters such as mirror diameter, focal length, grating magnification, and so on. As a result, we have identified the solution space that meets the EUVST science objectives and rocket envelope requirements. A single solution was selected and used to define the initial optical parameters for the concept study of the baseline architecture for defining the mission concept. For this solution, we optimized the grating and geometrical parameters by ray tracing of the Zemax software. Consequently, we found an optics system that fulfills the requirement for a 0.4" angular resolution over a field of view of 100" (including margins) covering spectral ranges of 170-215, 463-542, 557-637, 690-850, 925-1085, and 1115-1275 A. This design achieves an effective area 10 times larger than the Extreme-ultraviolet Imaging Spectrometer onboard the Hinode satellite, and will provide seamless observations of 4.2-7.2 log(K) plasmas for the first time. Tolerance analyses were performed based on the optical design, and the moving range and step resolution of focus mechanisms were identified. In the presentation, we describe the derivation of the solution space, optimization of the optical parameters, and show the results of ray tracing and tolerance analyses. Title: The Solar-C_EUVST mission Authors: Shimizu, Toshifumi; Imada, Shinsuke; Kawate, Tomoko; Ichimoto, Kiyoshi; Suematsu, Yoshinori; Hara, Hirohisa; Katsukawa, Yukio; Kubo, Masahito; Toriumi, Shin; Watanabe, Tetsuya; Yokoyama, Takaaki; Korendyke, Clarence M.; Warren, Harry P.; Tarbell, Ted; De Pontieu, Bart; Teriaca, Luca; Schühle, Udo H.; Solanki, Sami; Harra, Louise K.; Matthews, Sarah; Fludra, A.; Auchère, F.; Andretta, V.; Naletto, G.; Zhukov, A. Bibcode: 2019SPIE11118E..07S Altcode: Solar-C EUVST (EUV High-Throughput Spectroscopic Telescope) is a solar physics mission concept that was selected as a candidate for JAXA competitive M-class missions in July 2018. The onboard science instrument, EUVST, is an EUV spectrometer with slit-jaw imaging system that will simultaneously observe the solar atmosphere from the photosphere/chromosphere up to the corona with seamless temperature coverage, high spatial resolution, and high throughput for the first time. The mission is designed to provide a conclusive answer to the most fundamental questions in solar physics: how fundamental processes lead to the formation of the solar atmosphere and the solar wind, and how the solar atmosphere becomes unstable, releasing the energy that drives solar flares and eruptions. The entire instrument structure and the primary mirror assembly with scanning and tip-tilt fine pointing capability for the EUVST are being developed in Japan, with spectrograph and slit-jaw imaging hardware and science contributions from US and European countries. The mission will be launched and installed in a sun-synchronous polar orbit by a JAXA Epsilon vehicle in 2025. ISAS/JAXA coordinates the conceptual study activities during the current mission definition phase in collaboration with NAOJ and other universities. The team is currently working towards the JAXA final down-selection expected at the end of 2019, with strong support from US and European colleagues. The paper provides an overall description of the mission concept, key technologies, and the latest status. Title: Element Abundances: A New Diagnostic for the Solar Wind Authors: Laming, J. Martin; Vourlidas, Angelos; Korendyke, Clarence; Chua, Damien; Cranmer, Steven R.; Ko, Yuan-Kuen; Kuroda, Natsuha; Provornikova, Elena; Raymond, John C.; Raouafi, Nour-Eddine; Strachan, Leonard; Tun-Beltran, Samuel; Weberg, Micah; Wood, Brian E. Bibcode: 2019ApJ...879..124L Altcode: 2019arXiv190509319L We examine the different element abundances exhibited by the closed loop solar corona and the slow speed solar wind. Both are subject to the first ionization potential (FIP) effect, the enhancement in coronal abundance of elements with FIP below 10 eV (e.g., Mg, Si, Fe) with respect to high-FIP elements (e.g., O, Ne, Ar), but with subtle differences. Intermediate elements, S, P, and C, with FIP just above 10 eV, behave as high-FIP elements in closed loops, but are fractionated more like low-FIP elements in the solar wind. On the basis of FIP fractionation by the ponderomotive force in the chromosphere, we discuss fractionation scenarios where this difference might originate. Fractionation low in the chromosphere where hydrogen is neutral enhances the S, P, and C abundances. This arises with nonresonant waves, which are ubiquitous in open field regions, and is also stronger with torsional Alfvén waves, as opposed to shear (i.e., planar) waves. We discuss the bearing these findings have on models of interchange reconnection as the source of the slow speed solar wind. The outflowing solar wind must ultimately be a mixture of the plasma in the originally open and closed fields, and the proportions and degree of mixing should depend on details of the reconnection process. We also describe novel diagnostics in ultraviolet and extreme ultraviolet spectroscopy now available with these new insights, with the prospect of investigating slow speed solar wind origins and the contribution of interchange reconnection by remote sensing. Title: Stray light analysis and testing of the SoloHI (solar orbiter heliospheric imager) and WISPR (wide field imager for solar probe) heliospheric imagers Authors: Thernisien, Arnaud F. R.; Howard, Russell A.; Korendyke, Clarence; Carter, Tim; Chua, Damien; Plunkett, Simon Bibcode: 2018SPIE10698E..0ET Altcode: The techniques for stray light analysis, optimization and testing are described for two space telescopes that observe the solar corona: the Solar Orbiter Heliospheric Imager (SoloHI) that will fly on the ESA Solar Orbiter (SolO), and the Wide Field Imager for Solar Probe (WISPR) that will fly on the NASA Parker Solar Probe (PSP) mission. Imaging the solar corona is challenging, because the corona is six orders of magnitude dimmer than the Sun surface at the limb, and the coronal brightness continues to decrease to ten orders of magnitude below the Sun limb above 5° elongation from Sun center. The SoloHI and WISPR instruments are located behind their respective spacecraft heat shield. Each spacecraft heat shield does not block the instrument field of view above the solar limb, but will prevent direct sunlight entering the instrument aperture. To satisfy the instrument stray light attenuation required to observe the solar corona, an additional set of instrument baffles were designed and tested for successive diffraction of the heat shield diffracted light before entering the telescope entrance pupil. A semi empirical model of diffraction was used to design the baffles, and tests of the flight models were performed in flight like conditions with the aim of verifying the rejection of the design. Test data showed that the baffle systems behaved as expected. A second source of stray light is due to reflections of the sunlight off of the spacecraft structures and towards the instruments. This is especially the case for SoloHI where one of the spacecraft 8m tall solar arrays is located behind the telescope and reflects sunlight back onto the instrument baffles. The SoloHI baffle design had to be adjusted to mitigate that component, which was achieved by modifying their geometry and their optical coating. Laboratory tests of the flight model were performed. The test data were correlated with the predictions of a ray tracing model, which enabled the fine tuning of the model. Finally, end-to-end ray tracing was used to predict the stray light for the flight conditions. Title: Global Magnetospheric Imaging from the Deep Space Gateway in Lunar Orbit Authors: Chua, Damien H.; Socker, Dennis G.; Englert, Christoph R.; Carter, Michael T.; Plunkett, Simon P.; Korendyke, Clarence; Meier, Robert Bibcode: 2018tess.conf21265C Altcode: We propose to use the Deep Space Gateway (DSG) in lunar orbit as an observing platform for a magnetospheric imager that will capture the first direct global images of the interface between the incident solar wind and the Earth's magnetosphere, and the response of the coupled magnetosphere-plasmasphere-ionosphere system to all incident solar plasmas. The optical detection of the faint magnetosphere surrounding the bright Earth is achieved using the same techniques as those used to image the faint solar corona and solar wind. This method measures the brightness of visible that is Thomson-scattered by electrons in the solar wind and magnetospheric plasmas. The Thomson scattering brightness is proportional to the line of sight column electron density. The large-scale context afforded by globally imaging the magnetosphere promises major advances in our fundamental understanding of solar wind driving of the magnetosphere. Such images would reveal how electrons in the magnetosphere and plasmasphere are redistributed in response to solar wind forcing, particularly when CMEs and CIRs interact with geospace. Global images of the magnetosphere would also be useful for proving global boundary conditions to ionospheric specification models. Our global magnetospheric imager on DSG would be implemented as an externally mounted instrument suite that would not require any crew interaction under normal operation. The instrument suite would consist of an Earth-centered geocoronagraph (analogous to a solar coronagraph) with an external occulter of radius 1.2 - 1.5 Earth radii (RE) and a magnetospheric imager (analogous to a heliospheric imager). A geocoronagraph with an Earth-centered field of view of 25° would observe out to 26 RE from lunar orbit. This is sufficient to observe the entire cross section of the dayside magnetosphere, including the bow shock and magnetopause, the polar cusps, and a significant portion of the tail lobes. The magnetospheric imager would have an overlapping field of view approximately 30° wide that could be pointed upstream of the magnetosphere to image solar wind structures approaching the magnetosphere or downstream of Earth to observe the dynamics of the magnetotail plasma sheet. Title: Global Magnetospheric Imaging from the Deep Space Gateway in Lunar Orbit Authors: Chua, D. H.; Socker, D. G.; Englert, C. R.; Carter, M. T.; Plunkett, S. P.; Korendyke, C. M.; Meier, R. R. Bibcode: 2018LPICo2063.3161C Altcode: We propose to use the Deep Space Gateway as an observing platform for a magnetospheric imager that will capture the first direct global images of the interface between the incident solar wind and the Earth's magnetosphere. Title: Using the Deep Space Gateway to Build the Next Generation Heliophysics Research Grid Authors: Vourlidas, A.; Ho, G. C.; Cohen, I. J.; Korendyke, C. M.; Tun-Beltran, S.; Plunkett, S. P.; Newmark, J.; St Cyr, O. C.; Hoeksema, T. Bibcode: 2018LPICo2063.3055V Altcode: The Heliophysics Research Grid (HRG) consists of in situ and imaging sensors, distributed in key locations in the heliosphere for research and to support space exploration needs. The Deep Space Gateway enables the HRG as a storage and staging hub for HRG launches. Title: The Solar Orbiter Heliospheric Imager (SoloHI) for the Solar Orbiter Mission Authors: Howard, R.; Colaninno, R. C.; Plunkett, S. P.; Thernisien, A. F.; Wang, D.; Rich, N.; Korendyke, C.; Socker, D. G.; Linton, M.; McMullin, D. R.; Vourlidas, A.; Liewer, P. C.; De Jong, E.; Velli, M.; Mikic, Z.; Bothmer, V.; Philippe, L.; Carter, M. T. Bibcode: 2017AGUFMSH23D2681H Altcode: The SoloHI instrument has completed its development effort and has been integrated onto the Solar Orbiter (SolO) spacecraft. The SolO mission, scheduled for launch in February 2019, will undergo gravity assist maneuvers around Venus to change both the perihelion distance as well as the plane of the orbit to ultimately achieve a minimum perihelion of 0.28 AU and an orbital inclination of about 35° relative to the ecliptic plane. The remote sensing instruments will operate for three 10-day periods out of the nominal 6-month orbit. SoloHI will observe sunlight scattered by free electrons in the corona/solar wind from 5° to 45° elongation in visible wavelengths and will provide a coupling between remote sensing and in situ observations. It is very similar to the HI-1 instrument on STEREO/SECCHI except that the FOV is twice the size at 40o. We present our efforts to prepare for the mission including our observing plans, quick-look plans and some results of the calibration activities. We gratefully acknowledge the support of the NASA Solar Orbiter Collaboration project. Title: The Wide-Field Imager for the Parker Solar Probe Mission (WISPR) Authors: Plunkett, S. P.; Howard, R.; Chua, D. H.; Crump, N. A.; Dennison, H.; Korendyke, C.; Linton, M.; Rich, N.; Socker, D. G.; Thernisien, A. F.; Wang, D.; Vourlidas, A.; Baugh, R.; Van Duyne, J. P.; Liewer, P. C.; De Jong, E.; Boies, M. T.; Mikic, Z.; Bothmer, V.; Rochus, P.; Halain, J. P. Bibcode: 2017AGUFMSH23D2693P Altcode: The Parker Solar Probe (PSP) mission will be humanity's first visit to the atmosphere of our nearest star, the Sun, when it is launched in July 2018. PSP will complete 24 orbits between the Sun and Venus with diminishing perihelia reaching as close as 7 million km (9.86 solar radii) from Sun center. In addition to a suite of in-situ probes for the magnetic field, plasma, and energetic particles, the payload includes the Wide Field Imager for Solar Probe (WISPR) that will record unprecedented visible light images of the solar corona and the inner heliosphere. WISPR is the smallest heliospheric imager to date, and comprises two nested wide-field telescopes with large-format (2K x 2K) APS CMOS detectors to optimize the performance over a combined 95º radial by 58º transverse field of view and to minimize the risk of dust damage, which may be considerable close to the Sun. WISPR will discover - in this never-before explored region of the heliosphere - the fundamental nature of coronal structures and the source regions of the solar wind as the PSP flies through them, and will determine whether a dust-free zone exists near the Sun. WISPR has completed its development effort and has been integrated onto the PSP spacecraft. In this paper, we will present our efforts to prepare for the mission including our observing plans and some results of the calibration activities. Title: Stray light testing of WISPR baffle development model Authors: Hellin, M. -L.; Mazy, E.; Marcotte, S.; Stockman, Y.; Korendyke, C.; Thernisien, A. Bibcode: 2017SPIE10562E..4VH Altcode: Solar Probe Plus (SPP) is a NASA mission developed to visit and study the sun closer than ever before. SPP is designed to orbit as close as 7 million km (9.86 solar radii) from Sun center. One of its instruments: WISPR (Wide-Field Imager for Solar Probe Plus) will be the first `local' imager to provide the relation between the large-scale corona and the in-situ measurements. Title: The Ultraviolet Spectro-Coronagraph (UVSC) Pathfinder Experiment for the Remote Detection of Suprathermal Seed Particles: Instrument Status Authors: Strachan, Leonard; Laming, J. Martin; Ko, Yuan-Kuen; Tun Beltran, Samuel; Korendyke, Clarence M.; Brown, Charles M.; Socker, Dennis G.; Galysh, Ivan J.; Finne, Theodore T.; Eisenhower, Kevin C.; Brechbiel, David J.; Noya, Mario; Provornikova, Elena; Gardner, Larry D. Bibcode: 2017SPD....4811007S Altcode: The largest solar energetic particle (SEP) storms are produced by fast coronal mass ejection (CME) shocks. Efficient shock acceleration of ambient particles requires a near sun reservoir of suprathermal (proton) seed particles. However, the requisite seed particle reservoir has not been detected near the sun where CME shocks first appear. We are developing the Ultraviolet Spectro-Coronagraph (UVSC) Pathfinder space experiment to test for the presence or absence of the requisite suprathermal proton seed particle population within 3 solar radii of sun-center. In this poster, we present the instrument design concept, its development status, and the expected experimental results. The ultimate goal for the experiment is to demonstrate how such measurements can be used as a part of a future SEP space weather warning system. UVSC Pathfinder is scheduled to be launched in 2019 by the DoD Space Test Program. It is supported by funds from the Chief of Naval Research (via the NRL basic research program) and from NASA (via NDPR NNG13WF951 and NNH16AC29I). Title: LOCKYER (Large Optimized Coronagraph for KeY Emission line Research): A SMEX Mission to Provide Crucial Measurements of the Genesis of the Solar Wind and CMEs Authors: Ko, Y. K.; Vourlidas, A.; Korendyke, C.; Laming, J. M. Bibcode: 2016AGUFMSH43B2569K Altcode: The LOCKYER mission is designed to uncover the physical processes of acceleration and heating of the quiescent and transient solar wind. It builds on the success of the Ultraviolet Coronagraph Spectrometer (UVCS) on SOHO with a massive increase in effective area at Lyman-alpha (200x larger than UVCS), thanks to a modern optical design and the use of a 4m boom. The larger effective area enables spectral line observations from many ions, including He II (at 1640 Å), allowing us to access the region where the coronal plasma transitions from fluid to kinetic behavior. In addition, a visible light channel provides simultaneous high-resolution coronagraphic images for the global coronal structure and dynamics creating a greatly-expanded UVCS-LASCO `hybrid' instrument within the tight constraints of a SMEX mission. The LOCKYER mission aims to answer the following questions: 1) What are the physical processes responsible for the heating and acceleration of the primary (proton, electron, helium) and secondary (minor ion) plasma components of the fast and slow solar wind? 2) How are CMEs heated and accelerated? LOCKYER would greatly advance our knowledge of how and where the solar wind is formed, and how the variations in coronal microphysics impact the solar wind and heliosphere. The LOCKYER measurements are highly complementary to the Solar Probe Plus and Solar Orbiter measurements and provide detailed empirical descriptions of the coronal plasma at heights where the primary energy and momentum addition occur. Title: The Wide-Field Imager for Solar Probe Plus (WISPR) Authors: Vourlidas, Angelos; Howard, Russell A.; Plunkett, Simon P.; Korendyke, Clarence M.; Thernisien, Arnaud F. R.; Wang, Dennis; Rich, Nathan; Carter, Michael T.; Chua, Damien H.; Socker, Dennis G.; Linton, Mark G.; Morrill, Jeff S.; Lynch, Sean; Thurn, Adam; Van Duyne, Peter; Hagood, Robert; Clifford, Greg; Grey, Phares J.; Velli, Marco; Liewer, Paulett C.; Hall, Jeffrey R.; DeJong, Eric M.; Mikic, Zoran; Rochus, Pierre; Mazy, Emanuel; Bothmer, Volker; Rodmann, Jens Bibcode: 2016SSRv..204...83V Altcode: 2015SSRv..tmp....8V; 2015SSRv..tmp...66B The Wide-field Imager for Solar PRobe Plus (WISPR) is the sole imager aboard the Solar Probe Plus (SPP) mission scheduled for launch in 2018. SPP will be a unique mission designed to orbit as close as 7 million km (9.86 solar radii) from Sun center. WISPR employs a 95 radial by 58 transverse field of view to image the fine-scale structure of the solar corona, derive the 3D structure of the large-scale corona, and determine whether a dust-free zone exists near the Sun. WISPR is the smallest heliospheric imager to date yet it comprises two nested wide-field telescopes with large-format (2 K × 2 K) APS CMOS detectors to optimize the performance for their respective fields of view and to minimize the risk of dust damage, which may be considerable close to the Sun. The WISPR electronics are very flexible allowing the collection of individual images at cadences up to 1 second at perihelion or the summing of multiple images to increase the signal-to-noise when the spacecraft is further from the Sun. The dependency of the Thomson scattering emission of the corona on the imaging geometry dictates that WISPR will be very sensitive to the emission from plasma close to the spacecraft in contrast to the situation for imaging from Earth orbit. WISPR will be the first `local' imager providing a crucial link between the large-scale corona and the in-situ measurements. Title: The Ultraviolet Spectro-Coronagraph Pathfinder Mission for the Detection of Coronal Suprathermal Seed Particles Authors: Strachan, Leonard; Laming, J. Martin; Ko, Yuan-Kuen; Korendyke, Clarence M.; Tun Beltran, Samuel; Socker, Dennis G.; Brown, Charles; Provornikova, Elena Bibcode: 2016SPD....4730104S Altcode: The Ultraviolet Spectro-Coronagraph (UVSC) Pathfinder is a Naval Research Laboratory experiment designed to make the first detection of suprathermal seed particles close to the Sun. It uses an innovative “stacked” occulting system to significantly increase the effective light gathering power of a traditional, 1-meter length, externally occulted coronagraph. The external occultation in combination with a low scatter variable line spaced grating provide the stray light suppression needed to measure non-Maxwellian departures in the wings of the H Lyman alpha emission line profile. After the removal of other factors, these departures may be interpreted as the signature of suprathermal tails of the proton velocity distribution in the corona. UVSC Pathfinder will provide information on the origins and spatial/temporal variability of proton seed particle populations. We will discuss the accuracy needed to make such measurements and describe how the results can be used to develop a capability for predicting the onset of Solar Energetic Particle (SEP) storms. The experiment is scheduled for a launch by the DoD Space Test Program in late 2018/early 2019 and should have excellent overlap with the Solar Orbiter and Solar Probe Plus missions.UVSC Pathfinder is supported by funds from the Chief of Naval Research (via the NRL basic research program) and from NASA (via NDPR NNG13WF951 and NNH16AC29I). Title: Investigation of the Chromosphere-Corona Interface with the Upgraded Very High Angular Resolution Ultraviolet Telescope (VAULT2.0) Authors: Vourlidas, Angelos; Beltran, Samuel Tun; Chintzoglou, Georgios; Eisenhower, Kevin; Korendyke, Clarence; Feldman, Ronen; Moser, John; Shea, John; Johnson-Rambert, Mary; McMullin, Don; Stenborg, Guillermo; Shepler, Ed; Roberts, David Bibcode: 2016JAI.....540003V Altcode: Very high angular resolution ultraviolet telescope (VAULT2.0) is a Lyman-alpha (Lyα; 1216Å) spectroheliograph designed to observe the upper chromospheric region of the solar atmosphere with high spatial (<0.5‧‧) and temporal (8s) resolution. Besides being the brightest line in the solar spectrum, Lyα emission arises at the temperature interface between coronal and chromospheric plasmas and may, hence, hold important clues about the transfer of mass and energy to the solar corona. VAULT2.0 is an upgrade of the previously flown VAULT rocket and was launched successfully on September 30, 2014 from White Sands Missile Range (WSMR). The target was AR12172 midway toward the southwestern limb. We obtained 33 images at 8s cadence at arc second resolution due to hardware problems. The science campaign was a resounding success, with all space and ground-based instruments obtaining high-resolution data at the same location within the AR. We discuss the science rationale, instrument upgrades, and performance during the first flight and present some preliminary science results. Title: Waves and Magnetism in the Solar Atmosphere (WAMIS) Authors: Ko, Yuan-Kuen; Moses, John; Laming, John; Strachan, Leonard; Tun Beltran, Samuel; Tomczyk, Steven; Gibson, Sarah; Auchere, Frederic; Casini, Roberto; Fineschi, Silvano; Knoelker, Michael; Korendyke, Clarence; McIntosh, Scott; Romoli, Marco; Rybak, Jan; Socker, Dennis; Vourlidas, Angelos; Wu, Qian Bibcode: 2016FrASS...3....1K Altcode: Comprehensive measurements of magnetic fields in the solar corona have a long history as an important scientific goal. Besides being crucial to understanding coronal structures and the Sun’s generation of space weather, direct measurements of their strength and direction are also crucial steps in understanding observed wave motions. In this regard, the remote sensing instrumentation used to make coronal magnetic field measurements is well suited to measuring the Doppler signature of waves in the solar structures. In this paper, we describe the design and scientific values of the Waves and Magnetism in the Solar Atmosphere (WAMIS) investigation. WAMIS, taking advantage of greatly improved infrared filters and detectors, forward models, advanced diagnostic tools and inversion codes, is a long-duration high-altitude balloon payload designed to obtain a breakthrough in the measurement of coronal magnetic fields and in advancing the understanding of the interaction of these fields with space plasmas. It consists of a 20 cm aperture coronagraph with a visible-IR spectro-polarimeter focal plane assembly. The balloon altitude would provide minimum sky background and atmospheric scattering at the wavelengths in which these observations are made. It would also enable continuous measurements of the strength and direction of coronal magnetic fields without interruptions from the day-night cycle and weather. These measurements will be made over a large field-of-view allowing one to distinguish the magnetic signatures of different coronal structures, and at the spatial and temporal resolutions required to address outstanding problems in coronal physics. Additionally, WAMIS could obtain near simultaneous observations of the electron scattered K-corona for context and to obtain the electron density. These comprehensive observations are not provided by any current single ground-based or space observatory. The fundamental advancements achieved by the near-space observations of WAMIS on coronal field would point the way for future ground based and orbital instrumentation. Title: Waves and Magnetism in the Solar Atmosphere (WAMIS) Authors: Strachan, L.; Ko, Y. -K.; Moses, J. D.; Laming, J. M.; Auchere, F.; Casini, R.; Fineschi, S.; Gibson, S.; Knoelker, M.; Korendyke, C.; Mcintosh, S.; Romoli, M.; Rybak, J.; Socker, D.; Tomczyk, S.; Vourlidas, A.; Wu, Q. Bibcode: 2015IAUS..305..121S Altcode: Magnetic fields in the solar atmosphere provide the energy for most varieties of solar activity, including high-energy electromagnetic radiation, solar energetic particles, flares, and coronal mass ejections, as well as powering the solar wind. Despite the fundamental role of magnetic fields in solar and heliospheric physics, there exist only very limited measurements of the field above the base of the corona. What is needed are direct measurements of not only the strength and orientation of the magnetic field but also the signatures of wave motions in order to better understand coronal structure, solar activity, and the role of MHD waves in heating and accelerating the solar wind. Fortunately, the remote sensing instrumentation used to make magnetic field measurements is also well suited to measure the Doppler signature of waves in the solar structures. We present here a mission concept for the Waves And Magnetism In the Solar Atmosphere (WAMIS) experiment which is proposed for a NASA long-duration balloon flight. Title: The VAULT2.0 Observing Campaign: A Comprehensive Investigation of the Chromosphere-Corona Interface at Sub-arcsecond scales Authors: Vourlidas, A.; Korendyke, C.; Tun-Beltran, S. D.; Ugarte-Urra, I.; Morrill, J. S.; Warren, H. P.; Young, P.; De Pontieu, B.; Gauzzi, G.; Reardon, K. Bibcode: 2014AGUFMSH41C4155V Altcode: We report the first results from an observing campaign in support of the VAULT2.0 sounding rocket launch on September 30, 2014. VAULT2.0 is a Lya (1216Å) spectroheliograph capable of 0.3" (~250 km) spatial resolution. The objective of the VAULT2.0 project is the study of the chromosphere-corona interface. This interface has acquired renewed emphasis over the last few years, thanks to high-resolution observations from Hinode/SOT and EIS instruments and the Lya imaging from the two VAULT flights. The observations have shown that the upper chromosphere may play a more important role in heating the corona and in affecting EUV observations that previously thought: (1) by supplying the mass via Type-II spicules and, (2) by absorbing coronal emission. Many of the required clues for further progress are located in sub-arcsecond structures with temperatures between 10000 and 50000 K, a regime not accessible by Hinode or SDO. Lyman-alpha observations are, therefore, ideal, for filling in this gap. The observing campaign in support of the VAULT2.0 is closely coordinated with the Hinode and IRIS missions to study the mass/energy flow from the chromosphere to the corona with joint observations of type-II spicules, and the magnetic connectivity of coronal loops using the full imaging and spectral capabilities of IRIS, Hinode and SDO. Several ground-based observatories also provide important observations (IBIS, BBSO, SOLIS). The VAULT2.0 project is funded by the NASA LCAS program. Title: Observations of Near-Sun Turbulent Density Fluctuations with the Wide Field Imager for Solar Probe Plus (WISPR) Authors: Plunkett, S. P.; Howard, R.; Vourlidas, A.; Korendyke, C.; Rich, N.; Thernisien, A. F.; Wang, D.; Liewer, P. C. Bibcode: 2014AGUFMSH32A..05P Altcode: The trajectory of Solar Probe Plus (SPP) as it transits through the solar corona with a perihelion of < 10 Rs will allow much higher contrast observations of small-scale density fluctuations with higher cadence than is possible from 1 AU. The WISPR instrument will implement a high-cadence mode (up to 1 second) in which it will obtain images of the corona and inner heliosphere with high spatial resolution over a restricted field of view around specified regions of interest. Two-dimensional power spectra of the density fluctuations can then be constructed with variable cadences for direct comparison to similar spectra obtained by in-situ instruments on SPP and Solar Orbiter (SO). WISPR will provide density power spectra at or below the spectral break between inertial and injection scales, even at the closest perihelion approach, for different coronal structures. When combined with tomographic information from synoptic images, the WISPR turbulence program will be a major enhancement to the turbulence measurements from the SPP and SO in-situ instruments resulting in a much more robust understanding of the near-Sun turbulence. We will present details of the planned observations and will discuss the coordinated science objectives that can be addressed using these observations. Title: Waves and Magnetism in the Solar Atmosphere (WAMIS) Authors: Ko, Y. K.; Auchere, F.; Casini, R.; Fineschi, S.; Gibson, S. E.; Knoelker, M.; Korendyke, C.; Laming, J. M.; Mcintosh, S. W.; Moses, J. D.; Romoli, M.; Rybak, J.; Socker, D. G.; Strachan, L.; Tomczyk, S.; Vourlidas, A.; Wu, Q. Bibcode: 2014AGUFMSH53B4221K Altcode: Magnetic fields in the solar atmosphere provide the energy for most varieties of solar activity, including high-energy electromagnetic radiation, solar energetic particles, flares, and coronal mass ejections, as well as powering the solar wind. Despite the fundamental role of magnetic fields in solar and heliospheric physics, there exists only very limited measurements of the field above the base of the corona. What is needed are direct measurements of not only the strength and orientation of the magnetic field but also the signatures of wave motions in order to better understand coronal structure, solar activity and the role of MHD waves in heating and accelerating the solar wind. Fortunately, the remote sensing instrumentation used to make magnetic field measurements is also well suited for measuring the Doppler signature of waves in the solar structures. With this in mind, we are proposing the WAMIS (Waves and Magnetism in the Solar Atmosphere) investigation. WAMIS will take advantage of greatly improved infrared (IR) detectors, forward models, advanced diagnostic tools and inversion codes to obtain a breakthrough in the measurement of coronal magnetic fields and in the understanding of the interaction of these fields with space plasmas. This will be achieved with a high altitude balloon borne payload consisting of a coronagraph with an IR spectro-polarimeter focal plane assembly. The balloon platform provides minimum atmospheric absorption and scattering at the IR wavelengths in which these observations are made. Additionally, a NASA long duration balloon flight mission from the Antarctic can achieve continuous observations over most of a solar rotation, covering all of the key time scales for the evolution of coronal magnetic fields. With these improvements in key technologies along with experience gained from current ground-based instrumentation, WAMIS will provide a low-cost mission with a high technology readiness leve. Title: Progress toward high resolution EUV spectroscopy Authors: Korendyke, C.; Doschek, G. A.; Warren, H.; Young, P. R.; Chua, D.; Hassler, D. M.; Landi, E.; Davila, J. M.; Klimchuck, J.; Tun, S.; DeForest, C.; Mariska, J. T.; Solar C Spectroscopy Working Group; LEMUR; EUVST Development Team Bibcode: 2013SPD....44..143K Altcode: HIgh resolution EUV spectroscopy is a critical instrumental technique to understand fundamental physical processes in the high temperature solar atmosphere. Spectroscopic observations are used to measure differential emission measure, line of sight and turbulent flows, plasma densities and emission measures. Spatially resolved, spectra of these emission lines with adequate cadence will provide the necessary clues linking small scale structures with large scale, energetic solar phenomena. The necessary observations to determine underlying physical processes and to provide comprehensive temperature coverage of the solar atmosphere above the chromosphere will be obtained by the proposed EUVST instrument for Solar C. This instrument and its design will be discussed in this paper. Progress on the VEry high Resolution Imaging Spectrograph (VERIS) sounding rocket instrument presently under development at the Naval Research Laboratory will also be discussed. Title: A Space Weather Mission to the Earth's 5th Lagrangian Point (L5) Authors: Howard, R. A.; Vourlidas, A.; Ko, Y.; Biesecker, D. A.; Krucker, S.; Murphy, N.; Bogdan, T. J.; St Cyr, O. C.; Davila, J. M.; Doschek, G. A.; Gopalswamy, N.; Korendyke, C. M.; Laming, J. M.; Liewer, P. C.; Lin, R. P.; Plunkett, S. P.; Socker, D. G.; Tomczyk, S.; Webb, D. F. Bibcode: 2012AGUFMSA13D..07H Altcode: The highly successful STEREO mission, launched by NASA in 2006, consisted of two spacecraft in heliocentric orbit, one leading and one trailing the Earth and each separating from Earth at the rate of about 22.5 degrees per year. Thus the two spacecraft have been probing different probe/Sun/Earth angles. The utility of having remote sensing and in-situ instrumentation away from the Sun-Earth line was well demonstrated by STEREO. Here we propose the concept of a mission at the 5th Lagrangian "point" in the Earth/Sun system, located behind Earth about 60 degrees to the East of the Sun-Earth line. Such a mission would enable many aspects affecting space weather to be well determined and thus improving the prediction of the conditions of the solar wind as it impinges on geospace. For example, Coronal Mass Ejections can tracked for a significant distance toward Earth, new active regions can be observed before they become visible to the Earth observer, the solar wind can be measured before it rotates to Earth. The advantages of such a mission will be discussed in this presentation. Title: Exploring Small Spatial Scales in the Transition Region and Solar Corona with the Very High Angular Resolution Imaging Spectrometer (VERIS) Authors: Chua, D. H.; Korendyke, C. M.; Vourlidas, A.; Brown, C. M.; Tun-Beltran, S.; Klimchuk, J. A.; Landi, E.; Seely, J.; Davila, J. M.; Hagood, R.; Roberts, D.; Shepler, E.; Feldman, R.; Moser, J.; Shea, J. Bibcode: 2012AGUFMSH33A2217C Altcode: Theoretical and experimental investigations of the transition region and coronal loops point to the importance of processes occurring on small spatial scales in governing the strong dynamics and impulsive energy release in these regions. As a consequence, high spatial, temporal, and temperature resolution over a broad temperature range, and accuracy in velocity and density determinations are all critical observational parameters. Current instruments lack one or more of these properties. These observational deficiencies have created a wide array of opposing descriptions of coronal loop heating and questions such as whether or not the plasma within coronal loops is multi-thermal or isothermal. High spectral and spatial resolution spectroscopic data are absolutely required to resolve these controversies and to advance our understanding of the dynamics within the solar atmosphere. We will achieve this with the Very High Angular Resolution Imaging Spectrometer (VERIS) sounding rocket payload. VERIS consists of an off-axis paraboloid telescope feeding a very high angular resolution, extreme ultraviolet (EUV) imaging spectrometer that will provide the first ever, simultaneous sub-arcsecond (0.16 arcsecond/pixel) spectra in bright lines needed to study plasma structures in the transition region, quiet corona, and active region core. It will do so with a spectral resolution of >5000 to allow Doppler velocity determinations to better than 3 km/s. VERIS uses a novel two-element, normal incidence optical design with highly reflective, broad wavelength coverage EUV coatings to access a spectral range with broad temperature coverage (0.03-15 MK) and density-sensitive line ratios. Combined with Hinode Solar Optical Telescope (SOT) and ground based observatories, VERIS will deliver simultaneous observations of the entire solar atmosphere from the photosphere to the multi-million degree corona at sub-arcsecond resolution for the first time ever, allowing us to understand the missing link between chromospheric structures and the corona. VERIS will be launched from White Sands Missile Range in early 2013. This paper presents a progress report on the VERIS payload and a summary of observations planned to further our understanding of the fine-scale structure of individual coronal loops and the heating mechanisms operating within them. Title: LEMUR: Large European module for solar Ultraviolet Research. European contribution to JAXA's Solar-C mission Authors: Teriaca, Luca; Andretta, Vincenzo; Auchère, Frédéric; Brown, Charles M.; Buchlin, Eric; Cauzzi, Gianna; Culhane, J. Len; Curdt, Werner; Davila, Joseph M.; Del Zanna, Giulio; Doschek, George A.; Fineschi, Silvano; Fludra, Andrzej; Gallagher, Peter T.; Green, Lucie; Harra, Louise K.; Imada, Shinsuke; Innes, Davina; Kliem, Bernhard; Korendyke, Clarence; Mariska, John T.; Martínez-Pillet, Valentin; Parenti, Susanna; Patsourakos, Spiros; Peter, Hardi; Poletto, Luca; Rutten, Robert J.; Schühle, Udo; Siemer, Martin; Shimizu, Toshifumi; Socas-Navarro, Hector; Solanki, Sami K.; Spadaro, Daniele; Trujillo-Bueno, Javier; Tsuneta, Saku; Dominguez, Santiago Vargas; Vial, Jean-Claude; Walsh, Robert; Warren, Harry P.; Wiegelmann, Thomas; Winter, Berend; Young, Peter Bibcode: 2012ExA....34..273T Altcode: 2011ExA...tmp..135T; 2011arXiv1109.4301T The solar outer atmosphere is an extremely dynamic environment characterized by the continuous interplay between the plasma and the magnetic field that generates and permeates it. Such interactions play a fundamental role in hugely diverse astrophysical systems, but occur at scales that cannot be studied outside the solar system. Understanding this complex system requires concerted, simultaneous solar observations from the visible to the vacuum ultraviolet (VUV) and soft X-rays, at high spatial resolution (between 0.1'' and 0.3''), at high temporal resolution (on the order of 10 s, i.e., the time scale of chromospheric dynamics), with a wide temperature coverage (0.01 MK to 20 MK, from the chromosphere to the flaring corona), and the capability of measuring magnetic fields through spectropolarimetry at visible and near-infrared wavelengths. Simultaneous spectroscopic measurements sampling the entire temperature range are particularly important. These requirements are fulfilled by the Japanese Solar-C mission (Plan B), composed of a spacecraft in a geosynchronous orbit with a payload providing a significant improvement of imaging and spectropolarimetric capabilities in the UV, visible, and near-infrared with respect to what is available today and foreseen in the near future. The Large European Module for solar Ultraviolet Research (LEMUR), described in this paper, is a large VUV telescope feeding a scientific payload of high-resolution imaging spectrographs and cameras. LEMUR consists of two major components: a VUV solar telescope with a 30 cm diameter mirror and a focal length of 3.6 m, and a focal-plane package composed of VUV spectrometers covering six carefully chosen wavelength ranges between 170 Å and 1270 Å. The LEMUR slit covers 280'' on the Sun with 0.14'' per pixel sampling. In addition, LEMUR is capable of measuring mass flows velocities (line shifts) down to 2 km s - 1 or better. LEMUR has been proposed to ESA as the European contribution to the Solar C mission. Title: Observations from the HRTS-9 Rocket in the NUV Passband of the IRIS Mission Authors: Korendyke, C.; Morrill, J. S.; Floyd, L. E.; McMullin, D. R. Bibcode: 2011AGUFMSH13B1961K Altcode: The HRTS-9 rocket flew in April 1995 and observed a variety of solar surface features on the western portion of the solar disk. Unlike previous flights, the spectrograph was modified to observe a roughly 180 A wide portion the NUV solar spectrum near the Mg II doublet at 2800 A. In addition, a slit-jaw camera observed a 400 x 900 arcsecond region around the 960 arcsecond long (1 Rsun) x 1 arcsecond wide spectrograph slit in four UV passbands. Specifically, a series of narrowband images were measured at 1540 A (Si I), 1550 A ( C IV), 1560 A ( C I), and 1600 A (continuum). Images of H-alpha were measured as well. During the flight, the spectrograph slit was pointed at various features including the quiet sun near disk center and the limb, several active regions, and a sunspot. During the final portion of the flight, the rocket pointing was fixed and a slit scanning mechanism was used to collect a series of spectra that span about 45 arcseconds. From this data set spectral images at specific wavelengths in the 2765 to 2885 A range can be generated and compared to the broadband images at shorter wavelengths. For example, preliminary spectral images in the Mg II k line show evidence of loop structures similar to those seen in C IV. Our previous efforts with this data set has focused on the impact these radiance observations near Mg II have on solar spectral irradiance studies. These topics include examining the sources of solar irradiance variability, the center-to-limb variability of the quiet sun, and the relationship between the Mg II intensity and the photospheric magnetic field. In light of the upcomming IRIS Explorer mission, we are turning our attention to those science goals in order to anticipate and support potential observations by the IRIS NUV spectrograph channel. In this presentation we will present an overview of the available observations and previous results as well as discuss our ongoing analysis and preliminary spectral images of features in the region near Mg II. Title: Observations of the White Light Corona from Solar Orbiter and Solar Probe Plus Authors: Howard, R. A.; Thernisien, A. F.; Vourlidas, A.; Plunkett, S. P.; Korendyke, C. M.; Sheeley, N. R.; Morrill, J. S.; Socker, D. G.; Linton, M. G.; Liewer, P. C.; De Jong, E. M.; Velli, M. M.; Mikic, Z.; Bothmer, V.; Lamy, P. L. Bibcode: 2011AGUFMSH43F..06H Altcode: The SoloHI instrument on Solar Orbiter and the WISPR instrument on Solar Probe+ will make white light coronagraphic images of the corona as the two spacecraft orbit the Sun. The minimum perihelia for Solar Orbiter is about 60 Rsun and for SP+ is 9.5 Rsun. The wide field of view of the WISPR instrument (about 105 degrees radially) corresponds to viewing the corona from 2.2 Rsun to 20 Rsun. Thus the entire Thomson hemisphere is contained within the telescope's field and we need to think of the instrument as being a traditional remote sensing instrument and then transitioning to a local in-situ instrument. The local behavior derives from the fact that the maximum Thomson scattering will favor the electron plasma close to the spacecraft - exactly what the in-situ instruments will be sampling. SoloHI and WISPR will also observe scattered light from dust in the inner heliosphere, which will be an entirely new spatial regime for dust observations from a coronagraph, which we assume to arise from dust in the general neighborhood of about half way between the observer and the Sun. As the dust grains approach the Sun, they evaporate and do not contribute to the scattering. A dust free zone has been postulated to exist somewhere inside of 5 Rsun where all dust is evaporated, but this has never been observed. The radial position where the evaporation occurs will depend on the precise molecular composition of the individual grains. The orbital plane of Solar Orbiter will gradually increase up to about 35 degrees, enabling a very different view through the zodiacal dust cloud to test the models generated from in-ecliptic observations. In this paper we will explore some of the issues associated with the observation of the dust and will present a simple model to explore the sensitivity of the instrument to observe such evaporations. Title: LEMUR (Large European Module for solar Ultraviolet Research): a VUV imaging spectrograph for the JAXA Solar-C Mission Authors: Korendyke, Clarence M.; Teriaca, Luca; Doschek, George A.; Harra, Louise K.; Schühle, Udo H.; Shimizu, Toshifumi Bibcode: 2011SPIE.8148E..0IK Altcode: 2011SPIE.8148E..17K LEMUR is a VUV imaging spectrograph with 0.28" resolution. Incident solar radiation is imaged onto the spectrograph slit by a single mirror telescope consisting of a 30-cm steerable f/12 off-axis paraboloid mirror. The spectrograph slit is imaged and dispersed by a highly corrected grating that focuses the solar spectrum over the detectors. The mirror is coated with a suitable multilayer with B4C top-coating providing a reflectance peak around 18.5 nm besides the usual B4C range above 500Å. The grating is formed by two halves, one optimized for performances around 185Å and the other above 500Å. Three intensified CCD cameras will record spectra above 50 nm while a large format CCD array with an aluminum filter will be used around 185Å. Title: Earth-Affecting Solar Causes Observatory (EASCO): a mission at the Sun-Earth L5 Authors: Gopalswamy, Nat; Davila, Joseph M.; Auchère, Frédéric; Schou, Jesper; Korendyke, Clarence M.; Shih, Albert; Johnston, Janet C.; MacDowall, Robert J.; Maksimovic, Milan; Sittler, Edward; Szabo, Adam; Wesenberg, Richard; Vennerstrom, Suzanne; Heber, Bernd Bibcode: 2011SPIE.8148E..0ZG Altcode: 2011SPIE.8148E..30G; 2011arXiv1109.2929G Coronal mass ejections (CMEs) and corotating interaction regions (CIRs) as well as their source regions are important because of their space weather consequences. The current understanding of CMEs primarily comes from the Solar and Heliospheric Observatory (SOHO) and the Solar Terrestrial Relations Observatory (STEREO) missions, but these missions lacked some key measurements: STEREO did not have a magnetograph; SOHO did not have in-situ magnetometer. SOHO and other imagers such as the Solar Mass Ejection Imager (SMEI) located on the Sun-Earth line are also not well-suited to measure Earth-directed CMEs. The Earth-Affecting Solar Causes Observatory (EASCO) is a proposed mission to be located at the Sun-Earth L5 that overcomes these deficiencies. The mission concept was recently studied at the Mission Design Laboratory (MDL), NASA Goddard Space Flight Center, to see how the mission can be implemented. The study found that the scientific payload (seven remote-sensing and three in-situ instruments) can be readily accommodated and can be launched using an intermediate size vehicle; a hybrid propulsion system consisting of a Xenon ion thruster and hydrazine has been found to be adequate to place the payload at L5. Following a 2-year transfer time, a 4-year operation is considered around the next solar maximum in 2025. Title: The coronal suprathermal particle explorer (C-SPEX) Authors: Moses, J. Daniel; Brown, Charles; Doschek, George; Ko, Yuan-Kuen; Korendyke, Clarence; Laming, J. Martin; Socker, Dennis; Tylka, Allen; McMullin, Donald; Ng, Chee; Wassom, Steven; Lee, Martin; Auchère, Frédéric; Fineschi, Silvano; Carter, Tim Bibcode: 2011SPIE.8148E..0JM Altcode: 2011SPIE.8148E..18M The primary science objective of the Coronal Suprathermal Particle Explorer (C-SPEX) is to investigate the spatial and temporal variations of coronal suprathermal particle populations that are seeds for acceleration to solar energetic particles (SEPs). It is understood that such seed particle populations vary with coronal structures and can change responding to solar flare and coronal mass ejection (CME) events. Models have shown that higher densities of suprathermal protons can result in higher rates of acceleration to high energies. Understanding the variations in the suprathermal seed particle population is thus crucial for understanding the variations in SEPs. However, direct measurements are still lacking. C-SPEX will measure the variation in the suprathermal protons across various coronal magnetic structures, before/after the passage of CME shocks, in the post-CME current sheets, and before/after major solar flares. Understanding the causes for variation in the suprathermal seed particle population and its effect on the variation in SEPs will also help build the predictive capability of SEPs that reach Earth. The CSPEX measurements will be obtained from instrumentation on the International Space Station (ISS) employing well-established UV coronal spectroscopy techniques. Title: Straylight-Rejection Performance of the STEREO HI Instruments Authors: Halain, J. -P.; Eyles, C. J.; Mazzoli, A.; Bewsher, D.; Davies, J. A.; Mazy, E.; Rochus, P.; Defise, J. M.; Davis, C. J.; Harrison, R. A.; Crothers, S. R.; Brown, D. S.; Korendyke, C.; Moses, J. D.; Socker, D. G.; Howard, R. A.; Newmark, J. S. Bibcode: 2011SoPh..271..197H Altcode: 2011SoPh..tmp..189H; 2011SoPh..tmp..132H; 2011SoPh..tmp..258H The SECCHI Heliospheric Imager (HI) instruments on-board the STEREO spacecraft have been collecting images of solar wind transients, including coronal mass ejections, as they propagate through the inner heliosphere since the beginning of 2007. Title: Observations From The Hrts-9 Rocket In The Nuv Passband Of The Iris Mission Authors: Morrill, Jeff S.; Korendyke, C.; McMullin, D.; Floyd, L. Bibcode: 2011SPD....42.1730M Altcode: 2011BAAS..43S.1730M The HRTS-9 rocket flew in April 1995 and observed several solar surface features on the western solar disk. The HRTS-9 spectrograph was modified to observe a 180 A wide portion of the solar spectrum near MgII at 2800 A. Also, a slit-jaw camera observed a 400" x 900" region around the 960" long x 1" wide spectrograph slit in five passbands, specifically, 1540A (Si I), 1550A (C IV), 1560A (C I), 1600A, and images of H-alpha.

During the flight, the slit was pointed at various features including the quiet sun near disk center and the limb, active regions, and a sunspot. At the end of the flight, the pointing was fixed and a slit scanning mechanism was used to collect a series of spectra that span about 45". From this data set spectral images at specific wavelengths in the 2765 to 2885A range can be generated and compared to the broadband images at shorter wavelengths. For example, preliminary spectral images in the MgII k line show evidence of loop structures similar to those seen in C IV. Our previous efforts with this data set have focused on the impact these radiance observations near MgII have on solar spectral irradiance studies. These topics include examining the sources of solar irradiance variability, the center-to-limb variability of the quiet sun, and the relationship between the MgII intensity and the photospheric magnetic field. In light of the upcoming IRIS Explorer mission, we are turning our attention to those science goals in order to anticipate and support potential observations by the IRIS NUV spectrograph channel.

In this presentation we describe the available observations, previous results, as well as discuss our ongoing analysis and preliminary spectral images of features in the region near MgII. Work was sponsored by NASA. Title: The Coronal Suprathermal Particle Explorer (C-SPEX) Authors: Moses, John Daniel; Brown, C. M.; Doschek, G. A.; -. Ko, Y.; Korendyke, C. M.; Laming, J. M.; Rakowski, C. E.; Socker, D. G.; Tylka, A.; Ng, C. K.; Wassom, S. R.; McMullin, D. R.; Lee, M. A.; Auchere, F.; Fineschi, S. Bibcode: 2011SPD....42.1519M Altcode: 2011BAAS..43S.1519M The primary science objective of the Coronal Suprathermal Particle Explorer (C-SPEX) is to investigate the spatial and temporal variations of coronal suprathermal particle populations that are seeds for acceleration to solar energetic particles (SEPs). It is understood that such seed particle populations vary with coronal structures and can change responding to solar flare and coronal mass ejection (CME) events. Models have shown that higher densities of suprathermal protons can result in higher rates of acceleration to high energies. Understanding the variations in the suprathermal seed particle population is thus crucial for understanding the variations in SEPs. However, direct measurements are still lacking.

C-SPEX will measure the variation in the suprathermal protons across various coronal magnetic structures, before/after the passage of CME shocks, in the post-CME current sheets, and before/after major solar flares. The measurements will not only constrain models of SEP acceleration but also constrain models of the production of suprathermal particles from processes such as magnetic reconnection at the Sun. Understanding the causes for variation in the suprathermal seed particle population and its effect on the variation in SEPs will also help build the predictive capability of SEPs that reach Earth.

The C-SPEX measurements will be obtained from instrumentation on the International Space Station (ISS) employing well-established UV coronal spectroscopy techniques. The unique aspect of C-SPEX is a >100-fold increase of light gathering power over any previous UV coronal spectrometer. It is demonstrated C-SPEX will thus overcome the limitations in signal to noise that have thwarted prior attempts to observe suprathermals in the corona.

The present lack of a means to predict the variability of SEP intensities and the likelihood C-SPEX will help develop such predictions makes the proposed investigation directly relevant to each of the three strategic objectives of the NASA Heliophysics Research Strategic Objectives. Title: The Wide Field Imager for Solar PRobe (WISPR) Authors: Plunkett, S. P.; Howard, R. A.; Vourlidas, A.; Korendyke, C. M.; Socker, D. G.; Morrill, J. S.; Sheeley, N. R.; Linton, M.; Liewer, P. C.; de Jong, E. M.; Mikic, Z. Bibcode: 2010AGUFMSH11B1622P Altcode: The Wide Field Imager for Solar PRobe (WISPR) will image the Thomson-scattered light from the coronal plasma in the inner corona, with unprecedented spatial resolution, cadence, and sensitivity. WISPR follows on the SECCHI Heliospheric Imager (HI) aboard the STEREO mission, and addresses all four key objectives in the Solar Probe Plus: Report of the STDT (2008): (1) Determine the structure and dynamics of the magnetic fields at the sources of the fast and slow solar wind, (2) Trace the flow of energy that heats the solar corona and accelerates the SW, (3) explore the mechanisms that accelerate and transport energetic particles, (4) explore dusty plasma phenomena and their influence on the solar wind and energetic particle formation. Situated in the ram direction of the Solar Probe Plus (SPP) spacecraft (S/C), WISPR will have the unique ability to image the coronal structures when they are close to the Sun, as they approach, and as they pass over the spacecraft. As a remote sensor, WISPR will connect the structures close to the Sun to the spacecraft and provide important spatial and temporal information; measuring, for example, the properties of the structures generating the shocks and SEPs that will be measured in a few minutes at the S/C. Since the S/C is embedded in the corona, WISPR and the in situ instruments will measure for the first time the same plasma. Also as the SPP transits through the corona, the rapidly-varying viewpoint and high spatial resolution of WISPR will enable tomographic imaging of the corona, and lead to higher fidelity and finer scale 3D reconstructions than are possible with the STEREO mission or single-view rotational tomography. The wide field of view will include at times other inner heliospheric probes (e.g. Solar Orbiter) and will image the outflowing wind that is impinging on that probe. In addition to this standard imaging mode, WISPR opens a new capability for imaging instruments, the measurement of pressure turbulence by employing a high cadence mode (~1 sec) to image a small region in the corona. For the first time, the slopes of the power spectral density from images can be compared directly to the density and magnetic field fluctuations seen in situ as a function of coronal spatial structure and heliocentric distance. In addition, the 1 sec cadence can be generated anywhere within the WISPR field, enabling the study of the transition of the solar wind injected at the tops of the helmet streamers to inertial dissipation scales. Title: Imaging the Solar Wind with SoloHI Authors: Howard, R. A.; Vourlidas, A.; Plunkett, S. P.; Korendyke, C. M.; McMullin, D. R.; Liewer, P. C.; Velli, M. M.; Solohi Bibcode: 2010AGUFMSH11B1627H Altcode: Imaging outflows in the corona have been observed with the SOHO/LASCO instrument, since 1996. With the launch of the STEREO mission in 2006, these outflows can be followed into the heliosphere, with the SECCHI/Heliospheric Imager. For the Solar Orbiter mission, we have proposed an instrument called the Solar Orbiter Heliospheric Imager (SoloHI) to be able to image the solar wind and the density fluctuations in the wind and thus provide the link between the in-situ and remote sensing measurements. The nature of the Thomson scattering process integrates along a particular look direction but the scattering is a maximum on the Thomson sphere - the locus of points that form a right angle between the look direction and the solar vector. The experience from SECCHI/HI shows that the density fluctuations are easily visible and can be tracked back into the low corona, enabling a coupling between the solar wind plasma crossing the spacecraft and the source region in the corona. However, the SECCHI/HI observations have low cadence and long integration times. As a new observing mode for SoloHI, we have implemented a capability to readout a subset of the image at a time cadence of about 1 second. Thus small scale fluctuations can be observed in addition to the large scale fluctuations observed from SECCHI/HI. This will enable us to determine the spectral index of the density fluctuations over an unprecedented range of heights (from 5 to 135 Rsun) to compare with the in-situ determinations of the spectral index. This may indicate whether the fluctuations are generated close to the sun and convected out by the solar wind or are generated within the solar wind. Title: The Structure and Dynamics of the Upper Chromosphere and Lower Transition Region as Revealed by the Subarcsecond VAULT Observations Authors: Vourlidas, A.; Sanchez Andrade-Nuño, B.; Landi, E.; Patsourakos, S.; Teriaca, L.; Schühle, U.; Korendyke, C. M.; Nestoras, I. Bibcode: 2010SoPh..261...53V Altcode: 2009arXiv0912.2272V The Very high Angular resolution ULtraviolet Telescope (VAULT) is a sounding rocket payload built to study the crucial interface between the solar chromosphere and the corona by observing the strongest line in the solar spectrum, the Ly α line at 1216 Å. In two flights, VAULT succeeded in obtaining the first ever subarcsecond ( 0.5\hbox{$^''$} ) images of this region with high sensitivity and cadence. Detailed analyses of those observations contributed significantly to new ideas about the nature of the transition region. Here, we present a broad overview of the Ly α atmosphere as revealed by the VAULT observations and bring together past results and new analyses from the second VAULT flight to create a synthesis of our current knowledge of the high-resolution Ly α Sun. We hope that this work will serve as a good reference for the design of upcoming Ly α telescopes and observing plans. Title: Irradiance Calibration Using a Cryogenic Radiometer and a Broadband Light Source Authors: Morrill, J. S.; McMullin, D.; Floyd, L. E.; Lorentz, S. R.; Korendyke, C. M. Bibcode: 2009AGUFMSH13C..07M Altcode: Total solar irradiance measurements have been made from space based instruments for the past several decades. Due to a variety of reasons which range from instrumental degradation to differences in optical design, the data from these sources have proved difficult to overlap and place on an absolute scale. Some previous calibration efforts have used the sun as a source while operating the instrument in a large vacuum chamber. More recent efforts to provide ground based, pre-flight intercomparisons between flight radiometers and recently developed high power cryogenic radiometers using lasers. We are currently developing a calibration facility at The Naval Research Laboratory which uses a high power cryogenic radiometer with a broadband light source with near solar illumination. The system uses a very low scattered light vacuum calibration tank used to perform the stray light tests of the LASCO and SECCHI coronagraphs on the SOHO and STEREO missions. This presentation will address the status of our system, recent measurements, and future plans. Title: The Sub-arcsecond Structure Of The Upper Chromosphere: Results From The 2nd Flight Of The Nrl Vault Sounding Rocket Payload Authors: Sanchez-Andrade Nuno, Bruno; Vourlidas, A.; Korendyke, C. Bibcode: 2009SPD....40.2901S Altcode: The Very high Angular resolution ULtraviolet Telescope (VAULT) is an Lya spectroheliograph flown on a sounding rocket. The payload is capable of obtaining Lya filtergrams with a spatial resolution of around 0.33'' ( 200 km) over an extended field of view (535'' x 235'') . The instrument is tuned to the Ly-a line because it forms at the boundary of the upper chromosphere low corona. On its last flight, on 14 June 2002, VAULT observed an area around NOAA AR 9997 & 9998 with a rich variety of features: quiet Sun network, limb spicules, filaments, prominences and plage.

The observing campaign incorporated a wide variety of ground-based and space-borne instruments. The level 0.9 VAULT data is open and available from http://wwwsolar.nrl.navy.mil/rockets/vault .We have recently releseased SolarSoft-compatible software for easy access and processing of the data.

This contribution showcases the data capabilities and availability. We present contrast-enhanced images by means of wavelet image processing. The images reveal in extraordinary detail the dynamics of the smallest solar scales (200-300 km). We observe flows along thin threads on the prominence, exploding events on the plage and even in the quiet sun regions. Title: High-Resolution Center-to-Limb Variation of the Quiet Solar Spectrum near Mg II Authors: Morrill, J. S.; Korendyke, C. M. Bibcode: 2008ApJ...687..646M Altcode: The accurate determination of the center-to-limb variation of the quiet solar spectrum is of fundamental importance to our understanding of both spatially resolved solar spectral radiance as well as full-disk spectral irradiance. Previous studies have examined the center-to-limb variation at various spectral resolutions using both observations and calculations. Here we derive the center-to-limb variation near Mg II at 2800 Å from observations made by the HRTS-9 rocket-spectrograph at both high spatial (1'') and spectral (0.2 Å) resolution. This region of the solar spectrum is important because of its impact on the terrestrial atmosphere and its use in generating the Mg II index. The initial part of this paper presents the correction methods used to determine the center-to-limb variation, including the determination of the vignetting properties of the HRTS-9 instrument. This latter correction accounts for the intensity variation along the slit axis of the observed spectrogram. The resulting center-to-limb variation is employed in a model of solar spectral irradiance near Mg II. Using these results and calibrated solar spectra, the absolute intensity calibration is determined for the HRTS-9 spectra. An important aspect of the high-resolution center-to-limb variation is the presence of many spectral features illustrating the differences between the wings and cores of the numerous Fraunhofer lines in the 2765-2875 Å region. Also, both the Mg I and Mg II lines in this spectral region have broad, smooth wings that vary differently than the nearby line-blanketed continuum. The results of this study will provide a good source of comparison for detailed models of the quiet solar spectrum. Title: Janus: Observing the Sun-Earth Connection. A Lunar Mission Design Study Authors: Herman, J. R.; Davilla, J.; Korendyke, C.; Hamill, P. Bibcode: 2008LPICo1415.2004H Altcode: The Moon is a stable platform for obtaining simultaneous views of the Earth and Sun by the deployment of two proven instrument packages (Janus) on the moon's surface to understand the coupling between the Sun and Earth. Title: Wavelengths and Intensities of Spectral Lines in the 171-211 and 245-291 Å Ranges from Five Solar Regions Recorded by the Extreme-Ultraviolet Imaging Spectrometer (EIS) on Hinode Authors: Brown, C. M.; Feldman, U.; Seely, J. F.; Korendyke, C. M.; Hara, H. Bibcode: 2008ApJS..176..511B Altcode: We present spectral line wavelengths, identifications, and intensities in the 171-211 and 245-291 Å ranges from five solar plasma regions recorded by the Extreme-Ultraviolet Imaging Spectrometer (EIS) on Hinode. The recorded data were emitted from a quiet region, two active areas on the solar disk, a limb region, and a region 20'' above the limb. The line list contains 500 lines of which 55% were identified with previously known transitions. Although the EIS spectral coverage is limited to two ranges approximately 40 Å wide, the identified lines belong to a total of 56 ions from 15 elements. Title: High Resolution Center-To-Limb Variation of the Quiet Solar Spectrum Near Mg II Authors: Morrill, J. S.; Korendyke, C. M. Bibcode: 2008AGUSMSP21B..02M Altcode: The accurate determination of the high resolution center to limb variation of the solar spectrum is of fundamental importance to our understanding of both spatially resolved solar spectral radiance as well as full disk spectral irradiance. Previous studies have examined the center to limb variation at various spectral resolutions using both observations and calculations. In his study we derive the center to limb variation near Mg II at 2800 A from observations made by the HRTS rocket spectrograph at both high spatial (1-arc second) and spectral (0.077A) resolution. We present the details of the methods used in this derivation including the determination of the vignetting properties of the HRTS instrument. This latter correction accounts for the intensity variation along the slit axis of the observed spectrogram. The resulting center to limb variation is use in a model of solar spectral irradiance near Mg II. Using these results and calibrated solar irradiance spectra the absolute intensity calibration is generated for the HRTS spectra. An important aspect of the high resolution center to limb variation we present is the presence of many spectral features demonstrating the differences between the wings and cores of the numerous Fraunhofer lines in the 2765-2875 A region. In addition, both the Mg I and Mg II lines in this spectral region have very broad smooth wings with significant variation across these spectral features. The results of this study will provide a good source of comparison for detailed models of the solar spectrum. Title: Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) Authors: Howard, R. A.; Moses, J. D.; Vourlidas, A.; Newmark, J. S.; Socker, D. G.; Plunkett, S. P.; Korendyke, C. M.; Cook, J. W.; Hurley, A.; Davila, J. M.; Thompson, W. T.; St Cyr, O. C.; Mentzell, E.; Mehalick, K.; Lemen, J. R.; Wuelser, J. P.; Duncan, D. W.; Tarbell, T. D.; Wolfson, C. J.; Moore, A.; Harrison, R. A.; Waltham, N. R.; Lang, J.; Davis, C. J.; Eyles, C. J.; Mapson-Menard, H.; Simnett, G. M.; Halain, J. P.; Defise, J. M.; Mazy, E.; Rochus, P.; Mercier, R.; Ravet, M. F.; Delmotte, F.; Auchere, F.; Delaboudiniere, J. P.; Bothmer, V.; Deutsch, W.; Wang, D.; Rich, N.; Cooper, S.; Stephens, V.; Maahs, G.; Baugh, R.; McMullin, D.; Carter, T. Bibcode: 2008SSRv..136...67H Altcode: 2008SSRv..tmp...64H The Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) is a five telescope package, which has been developed for the Solar Terrestrial Relation Observatory (STEREO) mission by the Naval Research Laboratory (USA), the Lockheed Solar and Astrophysics Laboratory (USA), the Goddard Space Flight Center (USA), the University of Birmingham (UK), the Rutherford Appleton Laboratory (UK), the Max Planck Institute for Solar System Research (Germany), the Centre Spatiale de Leige (Belgium), the Institut d’Optique (France) and the Institut d’Astrophysique Spatiale (France). SECCHI comprises five telescopes, which together image the solar corona from the solar disk to beyond 1 AU. These telescopes are: an extreme ultraviolet imager (EUVI: 1 1.7 R), two traditional Lyot coronagraphs (COR1: 1.5 4 R and COR2: 2.5 15 R) and two new designs of heliospheric imagers (HI-1: 15 84 R and HI-2: 66 318 R). All the instruments use 2048×2048 pixel CCD arrays in a backside-in mode. The EUVI backside surface has been specially processed for EUV sensitivity, while the others have an anti-reflection coating applied. A multi-tasking operating system, running on a PowerPC CPU, receives commands from the spacecraft, controls the instrument operations, acquires the images and compresses them for downlink through the main science channel (at compression factors typically up to 20×) and also through a low bandwidth channel to be used for space weather forecasting (at compression factors up to 200×). An image compression factor of about 10× enable the collection of images at the rate of about one every 2 3 minutes. Identical instruments, except for different sizes of occulters, are included on the STEREO-A and STEREO-B spacecraft. Title: Heliospheric Images of the Solar Wind at Earth Authors: Sheeley, N. R., Jr.; Herbst, A. D.; Palatchi, C. A.; Wang, Y. -M.; Howard, R. A.; Moses, J. D.; Vourlidas, A.; Newmark, J. S.; Socker, D. G.; Plunkett, S. P.; Korendyke, C. M.; Burlaga, L. F.; Davila, J. M.; Thompson, W. T.; St. Cyr, O. C.; Harrison, R. A.; Davis, C. J.; Eyles, C. J.; Halain, J. P.; Wang, D.; Rich, N. B.; Battams, K.; Esfandiari, E.; Stenborg, G. Bibcode: 2008ApJ...675..853S Altcode: During relatively quiet solar conditions throughout the spring and summer of 2007, the SECCHI HI2 white-light telescope on the STEREO B solar-orbiting spacecraft observed a succession of wave fronts sweeping past Earth. We have compared these heliospheric images with in situ plasma and magnetic field measurements obtained by near-Earth spacecraft, and we have found a near perfect association between the occurrence of these waves and the arrival of density enhancements at the leading edges of high-speed solar wind streams. Virtually all of the strong corotating interaction regions are accompanied by large-scale waves, and the low-density regions between them lack such waves. Because the Sun was dominated by long-lived coronal holes and recurrent solar wind streams during this interval, there is little doubt that we have been observing the compression regions that are formed at low latitude as solar rotation causes the high-speed wind from coronal holes to run into lower speed wind ahead of it. Title: SECCHI Observations of the Sun's Garden-Hose Density Spiral Authors: Sheeley, N. R., Jr.; Herbst, A. D.; Palatchi, C. A.; Wang, Y. -M.; Howard, R. A.; Moses, J. D.; Vourlidas, A.; Newmark, J. S.; Socker, D. G.; Plunkett, S. P.; Korendyke, C. M.; Burlaga, L. F.; Davila, J. M.; Thompson, W. T.; St. Cyr, O. C.; Harrison, R. A.; Davis, C. J.; Eyles, C. J.; Halain, J. P.; Wang, D.; Rich, N. B.; Battams, K.; Esfandiari, E.; Stenborg, G. Bibcode: 2008ApJ...674L.109S Altcode: The SECCHI HI2 white-light imagers on the STEREO A and B spacecraft show systematically different proper motions of material moving outward from the Sun in front of high-speed solar wind streams from coronal holes. As a group of ejections enters the eastern (A) field of view, the elements at the rear of the group appear to overrun the elements at the front. (This is a projection effect and does not mean that the different elements actually merge.) The opposite is true in the western (B) field; the elements at the front of the group appear to run away from the elements at the rear. Elongation/time maps show this effect as a characteristic grouping of the tracks of motion into convergent patterns in the east and divergent patterns in the west, consistent with ejections from a single longitude on the rotating Sun. Evidently, we are observing segments of the "garden-hose" spiral made visible when fast wind from a low-latitude coronal hole compresses blobs of streamer material being shed at the leading edge of the hole. Title: Coronal Dimming Observed with Hinode: Outflows Related to a Coronal Mass Ejection Authors: Harra, Louise K.; Hara, Hirohisa; Imada, Shinsuke; Young, Peter R.; Williams, David R.; Sterling, Alphonse C.; Korendyke, Clarence; Attrill, Gemma D. R. Bibcode: 2007PASJ...59S.801H Altcode: Coronal dimming has been a signature used to determine the source of plasma that forms part of a coronal mass ejection (CME) for many years. Generally dimming is detected through imaging instruments such as SOHO EIT by taking difference images. Hinode tracked active region 10930 from which there were a series of flares. We combined dimming observations from EIT with Hinode data to show the impact of flares and coronal mass ejections on the region surrounding the flaring active region, and we discuss evidence that the eruption resulted in a prolonged steady outflow of material from the corona. The dimming region shows clear structure with extended loops whose footpoints are the source of the strongest outflow (≈ 40 kms-1). This confirms that the loops that are disrupted during the event do lose plasma and hence are likely to form part of the CME. This is the first time the velocity of the coronal plasma has been measured in an extended dimming region away from the flare core. In addition there was a weaker steady outflow from extended, faint loops outside the active region before the eruption, which is also long lasting. These were disturbed and the velocity increased following the flare. Such outflows could be the source of the slow solar wind. Title: Wavelength Determination for Solar Features Observed by the EUV Imaging Spectrometer on Hinode Authors: Brown, Charles M.; Hara, Hirohisa; Kamio, Suguru; Feldman, Uri; Seely, John F.; Doschek, George A.; Mariska, John T.; Korendyke, Clarence M.; Lang, James; Dere, Kenneth P.; Culhane, Len; Thomas, Roger J.; Davila, Joseph M. Bibcode: 2007PASJ...59S.865B Altcode: A wavelength calibration of solar lines observed by the high resolution EUV Imaging Spectrometer (EIS) on the Hinode satellite is reported. Spectral features of the quiet sun and of two mildly active areas were measured and calibrated. A listing of the stronger observed lines with identification of the leading contributor ions is presented. 41 lines are reported, with 90% identified. Wavelength precisions (2σ) of ±0.0031Å for the EIS short band and ±0.0029Å for the EIS long band are obtained. These lines, typical of 1-2 ×106 K plasmas, are recommended as standards for the establishment of EIS wavelength scales. The temperature of EIS varies by about 1D.5 C around the orbit and also with spacecraft pointing. The correlation of these temperature changes with wavelength versus pixel number scale changes is reported. Title: Progress Toward A Very High Angular Resolution Imaging Spectrometer (VERIS) Authors: Korendyke, Clarence M.; Vourlidas, A.; Landi, E.; Seely, J.; Klimchuck, J. Bibcode: 2007AAS...210.2604K Altcode: 2007BAAS...39Q.324K Recent imaging at arcsecond (TRACE) and sub-arcsecond (VAULT) spatial resolution clearly show that structures with fine spatial scales play a key role in the physics of the upper solar atmosphere. Both theoretical and observational considerations point to the importance of small spatial scales, impulsive energy release, strong dynamics, and extreme plasma nonuniformity. Fundamental questions regarding the nature, structure, properties and dynamics of loops and filamentary structures in the upper atmosphere have been raised.

To address these questions, we are developing a next generation, VEry high angular Resolution Imaging Spectrometer (VERIS) as a sounding rocket instrument. VERIS will obtain the necessary high spatial resolution, high fidelity measurements of plasma temperatures, densities and velocities. With broad simultaneous temperature coverage, the VERIS observations will directly address unresolved issues relating to interconnections of various temperature solar plasmas. VERIS will provide the first ever subarcsecond spectra of transition region and coronal structures. It will do so with a sufficient spectral resolution of to allow centroided Doppler velocity determinations to better than 3 km/s. VERIS uses a novel two element, normal incidence optical design with highly reflective EUV coatings to access a spectral range with broad temperature coverage (0.03-15 MK) and density-sensitive line ratios. Finally, in addition to the spectra, VERIS will simultaneously obtain spectrally pure slot images (10x150 arcsec) in the +/-1 grating orders, which can be combined to make instantaneous line-of-sight velocity maps with 8km/s accuracy over an unprecedented field of view.

The VERIS program is beginning the second year of its three year development cycle. All design activities and reviews are complete. Fabrication of all major components has begun. Brassboard electronics cards have been fabricated, assembled and tested. The paper presents the essential scientific characteristics of the instrument. Title: The EUV Imaging Spectrometer for Hinode Authors: Culhane, J. L.; Harra, L. K.; James, A. M.; Al-Janabi, K.; Bradley, L. J.; Chaudry, R. A.; Rees, K.; Tandy, J. A.; Thomas, P.; Whillock, M. C. R.; Winter, B.; Doschek, G. A.; Korendyke, C. M.; Brown, C. M.; Myers, S.; Mariska, J.; Seely, J.; Lang, J.; Kent, B. J.; Shaughnessy, B. M.; Young, P. R.; Simnett, G. M.; Castelli, C. M.; Mahmoud, S.; Mapson-Menard, H.; Probyn, B. J.; Thomas, R. J.; Davila, J.; Dere, K.; Windt, D.; Shea, J.; Hagood, R.; Moye, R.; Hara, H.; Watanabe, T.; Matsuzaki, K.; Kosugi, T.; Hansteen, V.; Wikstol, Ø. Bibcode: 2007SoPh..243...19C Altcode: The EUV Imaging Spectrometer (EIS) on Hinode will observe solar corona and upper transition region emission lines in the wavelength ranges 170 - 210 Å and 250 - 290 Å. The line centroid positions and profile widths will allow plasma velocities and turbulent or non-thermal line broadenings to be measured. We will derive local plasma temperatures and densities from the line intensities. The spectra will allow accurate determination of differential emission measure and element abundances within a variety of corona and transition region structures. These powerful spectroscopic diagnostics will allow identification and characterization of magnetic reconnection and wave propagation processes in the upper solar atmosphere. We will also directly study the detailed evolution and heating of coronal loops. The EIS instrument incorporates a unique two element, normal incidence design. The optics are coated with optimized multilayer coatings. We have selected highly efficient, backside-illuminated, thinned CCDs. These design features result in an instrument that has significantly greater effective area than previous orbiting EUV spectrographs with typical active region 2 - 5 s exposure times in the brightest lines. EIS can scan a field of 6×8.5 arc min with spatial and velocity scales of 1 arc sec and 25 km s−1 per pixel. The instrument design, its absolute calibration, and performance are described in detail in this paper. EIS will be used along with the Solar Optical Telescope (SOT) and the X-ray Telescope (XRT) for a wide range of studies of the solar atmosphere. Title: NRL EUV Imager: The Solar EUV Atmospheric Research Of The Corona And Heliosphere (SEARCH) Experiment Authors: Newmark, J. S.; Doschek, G. A.; Brown, C. M.; Cook, J. W.; Kilmchuk, J. A.; Korendyke, C. M.; Moses, J. D.; Myers, S. H.; Seely, J. F. Bibcode: 2007ESASP.641E..74N Altcode: Achieving the Solar Orbiter primary science goals requires knowledge of the fine structure of the solar atmosphere from chromospheric to coronal temperatures, and the structural links between these different temperature regions. An EUV imager is an ideal instrument for providing this crucial information, and the Solar Orbiter mission gives a unique opportunity to investigate the fine structure of the chromosphere, transition region, and corona at unprecedented high spatial resolution. We present a concept from the US Naval Research Laboratory (NRL) for providing an Extreme Ultraviolet (EUV) Imager for the Solar Orbiter mission, the "Solar EUV Atmospheric Research of the Corona and Heliosphere" (SEARCH) experiment. Title: Laboratory calibration of the Extreme-Ultraviolet Imaging Spectrometer for the Solar-B satellite Authors: Lang, James; Kent, Barry J.; Paustian, Wolfgang; Brown, Charles M.; Keyser, Christian; Anderson, Mark R.; Case, Giles C. R.; Chaudry, Rahil A.; James, Adrian M.; Korendyke, Clarence M.; Pike, C. David; Probyn, Brian J.; Rippington, David J.; Seely, John F.; Tandy, Jason A.; Whillock, Matthew C. R. Bibcode: 2006ApOpt..45.8689L Altcode: The laboratory end-to-end testing of the Extreme-Ultraviolet Imaging Spectrometer (EIS) for the Solar-B satellite is reported. A short overview of the EIS, which observes in two bands in the extreme-ultraviolet wavelength range, is given. The calibration apparatus is described, including details of the light sources used. The data reduction and analysis procedure are outlined. The wavelength calibration using a Penning source to illuminate the aperture fully is presented. We discuss the aperture determination using a radiometrically calibrated hollow-cathode-based source. We then give an account of the predicted and measured efficiencies from consideration of the efficiencies of individual optical elements in first order, an account of efficiencies out of band when radiation incident in one band is detected in the other, and efficiencies in multiple orders. The efficiencies measured in first order for in band and out of band are compared with the predictions and the sensitivity, and its uncertainties are derived. Application of the radiometric calibration is discussed. Title: Optics and mechanisms for the Extreme-Ultraviolet Imaging Spectrometer on the Solar-B satellite Authors: Korendyke, Clarence M.; Brown, Charles M.; Thomas, Roger J.; Keyser, Christian; Davila, Joseph; Hagood, Robert; Hara, Hirohisa; Heidemann, Klaus; James, Adrian M.; Lang, James; Mariska, John T.; Moser, John; Moye, Robert; Myers, Steven; Probyn, Brian J.; Seely, John F.; Shea, John; Shepler, Ed; Tandy, Jason Bibcode: 2006ApOpt..45.8674K Altcode: The Extreme-Ultraviolet Imaging Spectrometer (EIS) is the first of a new generation of normal-incidence, two-optical-element spectroscopic instruments developed for space solar extreme-ultraviolet astronomy. The instrument is currently mounted on the Solar-B satellite for a planned launch in late 2006. The instrument observes in two spectral bands, 170-210 Å and 250-290 Å. The spectrograph geometry and grating prescription were optimized to obtain excellent imaging while still maintaining readily achievable physical and fabrication tolerances. A refined technique using low ruling density surrogate gratings and optical metrology was developed to align the instrument with visible light. Slit rasters of the solar surface are obtained by mechanically tilting the mirror. A slit exchange mechanism allows selection among four slits at the telescope focal plane. Each slit is precisely located at the focal plane. The spectrograph imaging performance was optically characterized in the laboratory. The resolution was measured using the Mg iii and Ne iii lines in the range of 171-200 Å. The He ii line at 256 Å and Ne iii lines were used in the range of 251-284 Å. The measurements demonstrate an equivalent resolution of ∼2 arc sec⁡ on the solar surface, in good agreement with the predicted performance. We describe the EIS optics, mechanisms, and measured performance. Title: The extreme UV imaging spectrometer for the JAXA Solar-B mission Authors: Culhane, J. L.; Doschek, G. A.; Watanabe, T.; Smith, A.; Brown, C.; Hara, H.; Harra, L. K.; James, A. M.; al Janabi, K.; Kent, B.; Korendyke, C.; Lang, J.; Mariska, J.; Myers, S.; Seely, J.; Simnett, G.; Tandy, J.; Thomas, R.; Windt, D. L. Bibcode: 2006SPIE.6266E..0TC Altcode: 2006SPIE.6266E..22C The ISAS/JAXA Solar-B mission includes an Extreme-UV Imaging Spectrometer (EIS). It detects photons in the wavelength ranges 17 - 21 nm and 25 - 29 nm which include emission lines from several highly ionised species that exist at temperatures log T = 4.7, 5.6, 5.8, 5.9 and 6.0 - 7.3 K. Instrument throughput is increased substantially by the use of multilayer coatings optimized for maximum reflectance in the two selected wavelength bands. The use of back-illuminated CCDs provides significantly enhanced quantum efficiency over that previously available from microchannel plate systems. In this paper we will describe the design and operation of the instrument and present its performance parameters e.g. spectral and spatial resolution and sensitivity. Preliminary results of recent calibration measurements will be described. The role of EIS in the Solar-B mission will be illustrated with reference to the anticipated observing strategy for the first three months of the mission which will be outlined. Title: The Extreme Ultraviolet Imaging Spectrometer (EIS) on Solar-B Authors: Doschek, George A.; Brown, C. M.; Korendyke, C. M.; Mariska, J. T.; Myers, S. H.; Seely, J. F.; Dere, K. P.; Lang, J.; Culhane, J. L.; Watanabe, T. Bibcode: 2006SPD....37.3604D Altcode: 2006BAAS...38S.260D The Extreme Ultraviolet Imaging Spectrometer (EIS) for Solar-B is a high throughput state-of-the-art instrument designed to obtain solar spectra and images in two wavelength bands centered near 195 and 270 Angstroms. Traditional spectra can be obtained using narrow slits or images of solar structures can be obtained in individual spectral lines using wide slots. Essentially, the instrument obtains images in wavebands similar to TRACE but in each spectral line within the waveband. This removes electron temperature ambiguities inherent in broadband imagers and allows dynamic effects to be detected via Doppler shifts and densities and other plasma parameters to be measured via spectroscopic plasma diagnostics. After a brief description of how the instrument works and a comparison with previous instrumentation (sensitivity, etc.), the presentation will focus on the science that can be accomplished with EIS, presented in the form of sample observing sequences. The focus will be on active regions and solar flares with a consideration of topics such as temperature and density distributions in active region loops and their evolution, dynamical motions in active region loops, the reconnection site in solar flares, and temperature evolution of multimillion degree flare loops. Title: Calibration of the Soho/Lasco C3 White Light Coronagraph Authors: Morrill, J. S.; Korendyke, C. M.; Brueckner, G. E.; Giovane, F.; Howard, R. A.; Koomen, M.; Moses, D.; Plunkett, S. P.; Vourlidas, A.; Esfandiari, E.; Rich, N.; Wang, D.; Thernisien, A. F.; Lamy, P.; Llebaria, A.; Biesecker, D.; Michels, D.; Gong, Q.; Andrews, M. Bibcode: 2006SoPh..233..331M Altcode: We present a detailed review of the calibration of the LASCO C3 coronagraph on the SOHO satellite. Most of the calibration has been in place since early in the mission and has been utilized to varying degrees as required by specific analysis efforts. However, using observational data from the nearly decade-long database of LASCO images, we have re-evaluated and improved many aspects of the calibration. This includes the photometric calibration, vignetting function, geometric distortion, stray light, and exposure and observation times. Using this comprehensive set of corrections we have generated and made available a set of calibrated coronal images along with a set of periodic background images to ease the accessibility and use of the LASCO database. Title: Observing the Solar atmosphere with the Extreme Ultraviolet Imaging Spectrometer on Solar B Authors: Korendyke, C. M.; Brown, C.; Dere, K.; Doschek, G.; Klimchuk, J.; Landi, E.; Mariska, J.; Warren, H.; Lang, J. Bibcode: 2005AGUFMSH41B1124K Altcode: The Extreme Ultraviolet Imaging Spectrometer (EIS) is part of the instrument complement on the Solar B satellite, scheduled for launch in the summer of 2006. The instrument has been calibrated and is presently mounted on the spacecraft. EIS is the most sensitive EUV solar spectrometer to be flown. The instrument is the first of a new generation of two optical element, solar spectrographs. Preliminary results from the laboratory focussing and calibration of the instrument will be shown. The instrument wavelength coverage includes reasonably bright spectral lines emitted by plasmas from 0.1 to 20 MK in temperature. The wavelength range also provides coronal density diagnostics. Temperature, density and velocity diagnostics will be discussed. An example observing program for exploring active region evolution and dynamics will be discussed. Title: The correlation between features in the solar spectrum near Mg II and photospheric magnetic fields Authors: Morrill, J.; Korendyke, C.; Dere, K. Bibcode: 2005AGUSMSP41B..06M Altcode: During the HRTS-9 flight, spectrograms and spectroheliograms where obtained of the quiet sun, quiet limb, plage, and sunspots. Previous analysis of these observations required the correction of a small set of spectra for instrumental distortions and the absolute intensity calibration. We have applied these corrections to a larger portion of the HRTS-9 observations where the spectrograph slit was rastered across a small region of the sun along the solar equator. This set of corrected spectrograms has allowed us to generate high spatial and spectral resolution spectroheliograms of the observed quiet and active portions of the sun. In addition, with use of a magnetogram taken while the flight was in progress we have examined the relationship between the photospheric magnetic field and both Mg II emission at 280 nm and absorption features in the nearby solar spectrum due to both neutral and singly ionized species. In this presentation we will present our high resolution spectroheliograms as well as results showing the relationship between the magnetic field and several specific spectral features. Title: Structure and Organization of the Upper Chromosphere Authors: Korendyke, C. M.; Landi, E.; Vourlidas, A. Bibcode: 2005AGUSMSH12A..05K Altcode: Over its past two flights, the VAULT sounding rocket instrument obtained a series of subarcsecond resolution images of the solar disk. These Lyman alpha images resolve and separate structures in the upper chromosphere. The observed plasmas are concentrated in larger diameter, optically thick loops. The images taken near the limb unambiguously identify the height of the upper chromosphere in the quiet sun. An unexpected level of evolution and activity is present in the "quiet sun" at small spatial scales. The third flight of the payload will investigate the interconnectivity of the observed structures with the photosphere. Title: The Extreme Ultraviolet Imaging Spectrometer on Solar-B Authors: Mariska, J. T.; Brown, C. M.; Doschek, G. A.; Korendyke, C. M.; Myers, S. H.; Seely, J. F.; Dere, K. P.; Lang, J.; Culhane, J. L.; Watanabe, T. Bibcode: 2005AGUSMSP43A..02M Altcode: The Extreme Ultraviolet Imaging Spectrometer (EIS) is currently under development for flight on the Japanese Solar-B satellite. EIS uses a multilayer-coated off-axis telescope mirror and a multilayer-coated toroidal grating spectrometer to produce stigmatic spectra of solar regions isolated by a 1024 arcsec high slit. The instrument produces monochromatic images either by rastering the solar image across a narrow entrance slit or by using a very wide slit. Half of each optic is coated to optimize reflectance at 19.5 nm, and the other half to optimize reflectance at 27.0 nm, with each wavelength range imaged onto a separate CCD detector. EIS can provide key dynamical and density diagnostic information. Combining EIS data with observations from the other instruments on Solar-B should provide a detailed picture of solar atmospheric processes from the visible surface into the corona. In this presentation, we provide details of the instrument's expected performance based on calibration of the individual flight optics and end-to-end testing at the Rutherford Appleton Laboratory in the UK. Title: Calibration Results for the STEREO/SECCHI COR2 Coronagraphs Authors: Vourlidas, A.; Plunkett, S.; Korendyke, C.; Gong, Q.; Socker, D.; Howard, R. Bibcode: 2004AGUFMSH21B0409V Altcode: The two SECCHI instrument suites aboard the upcoming STEREO mission include the COR2 coronagraphs which observe the middle/outer corona; namely, from 2.5 to 15 solar radii. As of the end of August 2004, both COR2 instruments have been assembled and delivered to the SECCHI project and their perfomance has been measured and analyzed. The coronagraphs have met (and in some cases, exceeded) their performance requirements. Here, we present in detail the results of the calibration (photometry, polarization, stray light levels, etc) of the COR2 coronagraphs. We compare these new coronagraphs to the LASCO ones and discuss how they will contribute to the scientific success of the STEREO mission. Title: Calibration Results for the COR-1 Coronagraph on STEREO/SECCHI Authors: Thompson, W. T.; Davila, J. M.; Mentzell, E.; Korendyke, C. Bibcode: 2004AGUFMSH21B0408T Altcode: COR-1 is the inner coronagraph of the Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) instrument suite aboard the two STEREO spacecraft. COR-1 is a classic Lyot internally occulting coronagraph, observing the solar corona in broadband red light around 656 nm, from 1.35 to 4 solar radii. A linear polarizer is used to suppress scattered light, and to extract the polarized brightness signal from the solar corona. Calibration was performed in the Naval Research Laboratory vacuum tunnel facility previously used for the LASCO experiment aboard SOHO. We report on the results for scattered light, photometric calibration, resolution, and polarization. All performance requirements are met or exceeded. Based on these results, we demonstrate that COR-1 will be able to carry out its scientific mission. Title: Solar UV Spectral Radiance from SKYLAB Authors: Morrill, J.; Korendyke, C.; Dere, K. Bibcode: 2004AGUFMSH53A0305M Altcode: As part of an ongoing NASA-LWS sponsored research program, solar UV spectral radiance has been determined for the quiet sun at a variety of center-to-limb positions observed by the SO82B UV spectrograph on SKYLAB. This has been done using a high quality flatbed scanner to digitize the SKYLAB film data. The goal of the present program is to develop a spectral irradiance model that utilizes the full resolution of the SKYLAB spectra (~ 0.010 nm at 300 nm). The model requires detailed knowledge of the center-to-limb variation (CLV) at full resolution over the 200 - 400nm wavelength range. This information is also required to determine the absolute intensity calibration which uses full-disk irradiance measurements from UARS (SOLSTICE and SUSIM) in addition to the CLV. This calibration is then used to derive the disk center radiance. In addition to the quiet sun, spectra of sunspots and active regions are also being digitized and an attempt is underway to derive the CLV for these surface morphologies as well. Further, spectra at shorter wavelength (~120 - 200nm) are being examined in order to extend the wavelength coverage of these radiance and CLV results. In this presentation we will present the details of the analysis methods and results for the quiet sun. Ongoing work on sunspots and active regions will be presented as will results involving work on shorter wavelength spectra. Title: Solar ultraviolet spectro-coronagraph with toroidal varied line-space (TVLS) grating Authors: Fineschi, Silvano; Korendyke, Clarence M.; Moses, J. Dan; Thomas, Roger J. Bibcode: 2004SPIE.5487.1165F Altcode: This paper describes an instrument for imaging spectroscopy of ultraviolet (UV) line emission from the solar corona, in the 0.3-1.2x102 nm wavelength range. The optical design for this Ultraviolet Spectro-Coronagraph (UVSC) is an externally occulted, off-axis Gregorian telescope where the secondary mirror is a Toroidal Varied Line-Space (TVLS) grating. A field stop with multiple slits is at the prime focus of the telescope"s mirror. This multi-slit field stop is the entrance aperture for the spectrograph. The slits select a number of strips in the field-of-view (FOV) with enough separation to minimize the spectral overlap of the UV lines dispersed by the TVLS grating. This type of gratings allows for a much larger stigmatic FOV (i.e., 3° x 4°) in both the spatial and spectral direction than that of the Toroidal Uniform Line-Space (TULS) gratings. The complete imaging of the FOV is obtained by interpolating the slit images along the spectral dispersion direction. As an example, this paper discusses the possible use of a UVSC instrument on HERSCHEL, a NASA sounding-rocket payload, and on Solar Orbiter (SOLO), an ESA mission. HERSCHEL includes the Sounding CORona Experiment (SCORE) that comprises a UV Coronagraphic Imager (UVCI) for narrow-band (i.e., λ/Δλ≈10) imaging of the HeII, 30.4 nm, line. How a spectroscopic capability (i.e., λ/▵λ ≈0.3-1 x 104) would enhance the HERSCHEL science is discussed. The SOLO mission is planned for launch in 2013. Its orbital profile will bring the spacecraft as close to the Sun as 0.22 A.U. Also SOLO would represent an ideal and unique platform for a compact UVSC instrument (i.e., ≈ 1-m length) capable of obtaining simultaneous imaging and spectroscopy of the UV corona. The expected optical performances are presented for a UVSC/SOLO optimised for the OVI doublet, 103.2/103.7 nm. Title: A Comparison of the Mg II Index Derived from Estimated and Observed Solar Spectra Authors: Morrill, J.; Korendyke, C.; Dere, K. Bibcode: 2004AAS...204.7207M Altcode: 2004BAAS...36..799M We have estimated values of the Mg II index using a model of solar spectral irradiance developed at the Naval Research Laboratory. This model uses Ca II K images and spatially resolved sun spot, quiet sun, and active sun spectra measured by the HRTS-9 rocket to generate the estimated spectra. These spectra are compared to observed spectra such as the UARS-SUSIM and UARS-SOLSTICE data sets. In order to further compare the observed and estimated spectra, a Mg II index is derived from these two sets of spectra. In this presentation we will review the details of the model, discuss the methods of deriving the Mg II index, and compare the Mg II variability resulting from the observed and estimated spectra. Title: Performance of multilayer-coated gratings for the extreme-ultraviolet imaging spectrometer (EIS) for the Solar-B mission Authors: Seely, John F.; Windt, David L.; Donguy, Soizik; Brown, Charles; Holland, Glenn; Hunter, William R.; Kowalski, Michael P.; Kjornrattanawanich, Benjawan; Doschek, George; Mariska, John; Korendyke, Clarence; Dere, Ken Bibcode: 2004SPIE.5168...12S Altcode: The measured efficiencies of two flight gratings and the reflectances of two flight mirrors developed for the Extreme-Ultraviolet Imaging Spectrometer (EIS) for the Japanese Solar-B mission are presented. Each optic has two sectors with Mo/Si multilayers that refelct the 17 - 21 nm and 25 - 29 nm wavebands at normal incidence. The efficiencies that were measured using monochromatic synchrotron radiation are in good agreement with the calculated efficiencies. Title: Visible, externally occulted coronagraph for Solar Orbiter Authors: Vives, Sebastien; Lamy, Philippe L.; Korendyke, Clarence Bibcode: 2004SPIE.5171..131V Altcode: The SIde-Looking Coronagraph (SILC) is one of the solar remote-sensing instruments proposed for the payload of the Solar Orbiter mission. The Solar Orbiter is a mission selected in September 2000 by the European Space Agency (ESA) for the definition study phase. The Solar Orbiter will describe elliptic orbits with a large range of heliocentric distance, from 0.21 to 0.6 AU (astronomical units), that is a factor 3 for the geometric conditions and will reach heliographic latitudes as high as 38 degrees. Furthermore, the spacecraft will have offset pointing capability so as to target any point of the solar disk. These constraints (in addition to the severe thermal environment) lead us to propose an externally occulted coronagraph entirely protected from direct sunlight by remaining in the shadow of the spacecraft and looking sideways. The optical design follows the general principles of an externally-occulted coronagraph adapted to the side-looking concept. Although SILC loses the full spatial coverage of the corona, it can observe the inner part of the corona (down to 1.5R) during the whole mission and compensate the off-pointing of the spacecraft in the two directions. The performances, resulting from ray-tracing calculations, are presented here together with the expected stray light level. Title: The SIde-Looking Coronagraph (SILC) for the Solar Orbiter mission Authors: Vives, S.; Lamy, P.; Korendyke, C. Bibcode: 2004cosp...35..951V Altcode: 2004cosp.meet..951V The SIde-Looking Coronagraph (SILC) is one of the solar remote-sensing instruments proposed for the payload of the Solar Orbiter mission (European Space Agency, ESA). The Solar Orbiter will describe elliptic orbits with a large range of heliocentric distance, from 0.21 to 0.6 AU, that is a factor 3 for the geometric conditions, and will reach heliographic latitudes as high as 38 degrees. Furthermore, the spacecraft will have offset pointing capability so as to target any point of the solar disk. These specificities (in addition to the severe thermal environment) are very restrictive for a coronagraph and lead us to propose an externally occulted coronagraph entirely protected from direct sunlight by remaining in the shadow of the spacecraft and looking sideways. The optical design follows the general principles of an externally-occulted coronagraph adapted to the side-looking concept. Although SILC loses the full spatial coverage of the corona, it can observe the inner part of the corona (down to 1.5 solar radii) during the whole mission and compensate the off-pointing of the spacecraft in the two directions. The performances, resulting from ray-tracing calculations, will be presented together with the first measurements of the stray light level. Title: LASCO C2 and C3 Level-1 Images: Calibration and Pipeline Processing Authors: Thernisien, A. F.; Morrill, J.; Llebaria, A.; Rich, N.; Vourlidas, A.; Esfandiari, E.; Wang, D.; Korendyke, C.; Moses, D.; Biesecker, D.; Bout, M.; Lamy, P.; Howard, R. A. Bibcode: 2003AGUFMSH41B0461T Altcode: The LASCO C2 and C3 coronagraphs have provided coronal observations since May, 1996. Initial calibrations have been available during most of this time period. We have subsequently completed a re-evaluation and refinement of these calibration procedures. We are now able to present the final version of the level-1 data using the latest improvements from in-flight calibration results. Further details on the LASCO calibration and level-1 data access are presented at http://lasco-www.nrl.navy.mil/level_1/lascocal_index.html. In this presentation we will sum up the different aspects of the LASCO C2-C3 image corrections such as vignetting, absolute photometry, time corrections, geometric distortion, sun center position, and spacecraft orientation. Title: High-Resolution Views of the Solar Atmosphere Authors: Vourlidas, A.; Korendyke, C. Bibcode: 2003SPD....34.2009V Altcode: 2003BAAS...35..845V The study of many of the outstanding phenomena of the solar atmosphere (coronal heating, flares and coronal mass ejection) has persistently shown that observations of physical processes at ever smaller scales are needed for their understanding. Here I report on the results from the latest NRL sounding rocket payload, the Very Advanced ULtraviolet Telescope (VAULT). In two successful flights, the instrument achieved 0.33 arcsecond resolution, the highest ever from a space platform. VAULT obtained spectrally pure images of the upper chromosphere/lower transition region in the Lya line (1216A). A number of space-borne and ground-based obsrvatories supported the VAULT flights. The first results from the analysis of these datasets will be presented. Title: Expected Performance of the Extreme Ultraviolet Imaging Spectrometer on Solar-B Authors: Mariska, J. T.; Brown, C. M.; Dere, K. P.; Doschek, G. A.; Korendyke, C. M.; Myers, S. H.; Seely, J. F.; Culhane, J. L.; Watanabe, T. Bibcode: 2003SPD....34.2006M Altcode: 2003BAAS...35..845M The Extreme Ultraviolet Imaging Spectrometer (EIS) is currently under development for flight on the Japanese Solar-B satellite. EIS uses a multilayer-coated off-axis telescope mirror and a multilayer-coated toroidal grating spectrometer to produce stigmatic spectra of solar regions isolated by a 1024 arcsec high slit. The instrument produces monochromatic images either by rastering the solar image across a narrow entrance slit or by using a very wide slit. Half of each optic is coated to optimize reflectance at 19.5 nm, and the other half to optimize reflectance at 27.0 nm, with each wavelength range imaged onto a separate CCD detector.

In this presentation we provide an update on the EIS hardware development and show details of the expected performance of the instrument in solar quiet regions, active regions, and flares. Title: High Resolution Limb Darkening Function Near 2800 /AA/ Measured by HRTS Authors: Morrill, J. S.; Dere, K. P.; Korendyke, C. M. Bibcode: 2003SPD....34.1909M Altcode: 2003BAAS...35..843M We are currently developing an empirical model of solar spectral irradiance varaibility. This model will combine ground based observations of the areas and locations of plage and sunspots with measured wavelength dependent contrast factors in order to estimate the solar spectrum. One important component of this model is the wavelength dependent limb darking function that must be determined at high resolution. Using quiet sun spectra near Mg II at about 2800 /AA/ measured by the NRL HRTS instrument, we have recently determined this function for the quiet sun. This function shows many features similar to those seen in the active region contast that we have reported earlier. In this presentation we will discuss the method of determining the limb darkening function in the 2765 -2885 /AA/ region and it's impact on the irradiance model. Title: The Reconnection And Microscale (RAM) Solar-Terrestrial Probe Authors: Bookbinder, Jay A.; DeLuca, Edward; Cheimets, Peter; Golub, Leon; Hassler, Donald M.; Korendyke, Clarence M.; Glenn, Paul E.; Silver, Eric H. Bibcode: 2003SPIE.4853..436B Altcode: A hot, magnetized plasma such as the solar corona has the property that much of the physics governing its activity takes place on remarkably small spatial and temporal scales, while the response to this activity occurs on large scales. Observations from SMM, TRACE, SOHO and Yohkoh have shown that typical solar active regions have loops ranging in temperature from 0.5 to 10 MK, and flares up to 40MK. The spatial and temporal domains involved have been heretofore inaccessible to direct observations from Earth, so that theory has relied heavily on extrapolations from more accessible regimes, and on speculation. The RAM Solar-Terrestrial Probe consists of a set of carefully selected imaging and spectroscopic instruments that enable definitive studies of the dynamics and energetics of the solar corona. Title: Calibration of the LASCO C3 Coronal Images Authors: Morrill, J.; Biesecker, D.; Esfandiari, A.; Korendyke, C.; Moses, D.; Rich, N.; Vourlidas, A.; Wang, D.; Howard, R. A.; Lamy, P.; Llebaria, A.; Thernisien, A. Bibcode: 2002AAS...200.5503M Altcode: 2002BAAS...34R.732M The LASCO C3 coronagraph has provided coronal observations since May, 1996. Preliminary calibrations have been available during most of this time period. However, some aspects of the calibration have required re-evaluation and we are just completing a complete review of the calibration procedure for these images. In this presentation we will discuss the steps required to correct LASCO C3 images. This includes corrections required by both optical and electrical characteristics of the instrument as well as timimg and spacecraft pointing driven correctons. Title: On the Correlation between Coronal and Lower Transition Region Structures at Arcsecond Scales Authors: Vourlidas, A.; Klimchuk, J. A.; Korendyke, C. M.; Tarbell, T. D.; Handy, B. N. Bibcode: 2001ApJ...563..374V Altcode: We compare the morphology of active region structures observed in the 171 Å (T~9×105 K) and Lyα (T~2×104 K) lines. The coronal data were obtained by the Transition Region and Coronal Explorer (TRACE) in support of the Very High Angular Resolution Ultraviolet Telescope (VAULT) sounding rocket launch, which acquired subarcsecond resolution images of an active region in the Lyα line, on 1999 May 7. Using a pair of calibrated, nearly simultaneous images, we find that: (i) a very good correlation exists between the Lyα and 171 Å intensities in the TRACE moss regions, (ii) we can identify several identical structures in some (but not all) moss areas, and (iii) the correlations are greatly reduced at the footpoints of the 171 Å large-scale loops. We derive a lower limit for the Lyα emission measure, under the assumption of effectively optically thin emission, and compare it to the 171 Å emission measure. As in previous studies, we find an excess of Lyα material compared to the amount expected for a thermal conduction-dominated corona-chromosphere transition region, even for structures that appear to be identical in the two wavelengths. This result implies that some other mechanism besides classical heat conduction from the corona must contribute to the observed Lyα intensities. The observations do not support the idea of a physically distinct cool loop component within active regions. Title: Solar Irradiance Variability Modeled Near Mg II Using Plage and Sunspot Contrast Factors Measured by HRTS Authors: Morrill, J. S.; Dere, K. P.; Korendyke, C. M.; Floyd, L. E. Bibcode: 2001AGUFMSH11C0733M Altcode: Empirical models of solar spectral irradiance varaibility combine areas and locations of plage and sunspots with wavelength dependent contrast factors in order to estimate the solar spectrum. At UV wavelengths, these models have relied on estimated or calculated contrast factors that are often at low resolution. Using quiet sun, plage, and sunspot spectra near Mg II at ~ 2800Å measured by the NRL HRTS instrument, we have recently determined the wavelength dependent contrast factors for plage and sunspots. In this presentation we will discuss the use of measured contrast factors in a spectral irradiance model of the 2765 - 2885Å region and the preliminary comparisons of model results with SUSIM observations. These comparisons will examine spectral irradiance variations on solar rotational and solar cycle time scales. Title: The Sources of Solar Ultraviolet Variability between 2765 and 2885 Å: Mg I, Mg II, Si I, and Continuum Authors: Morrill, J. S.; Dere, K. P.; Korendyke, C. M. Bibcode: 2001ApJ...557..854M Altcode: The variation of the solar spectrum between 2000 and 4000 Å is a major component of the total irradiance variability of the Sun. Recent analyses suggest that variations in the solar ultraviolet flux at these wavelengths account for about 30% of the total solar irradiance variability. Most estimates of solar spectral irradiance variability in the ultraviolet are based on the ratio of the intensity of features such as solar plages and sunspots to the intensity of the quiet Sun. These ratios are referred to as contrast factors. To a large degree, contrast factors at ultraviolet wavelengths have not been measured. We present measurements of the average intensities of plage, sunspot, and quiet-Sun regions in the spectral range between 2765 and 2885 Å, derived from high spatial and spectral resolution spectra obtained during the ninth rocket flight of the High Resolution Telescope and Spectrograph in 1995. From these average spectra, plage and sunspot contrast factors are determined. To our knowledge, these are the first contrast factors at these wavelengths derived from measured solar intensities. These spectra show a large contrast in the Mg I, Mg II, and Si I Fraunhofer lines and a much smaller contrast (1.01+/-0.015 to 1.04+/-0.04) in the line-blanketed continuum. Contrast factors are also determined for three intensity levels of the quiet Sun as well as for a single sunspot. Many fine spectral features in the contrast factors can be attributed to weak Fraunhofer lines of Cr II, Fe I, Fe II, and Mg I. Title: High-resolution Imaging of the Upper Solar Chromosphere: First Light Performance of the Very-high-Resolution Advanced ULtraviolet Telescope Authors: Korendyke, C. M.; Vourlidas, A.; Cook, J. W.; Dere, K. P.; Howard, R. A.; Morrill, J. S.; Moses, J. D.; Moulton, N. E.; Socker, D. G. Bibcode: 2001SoPh..200...63K Altcode: The Very-high-resolution Advanced ULtraviolet Telescope (VAULT) experiment was successfully launched on 7 May 1999 on a Black Brant sounding rocket vehicle from White Sands Missile Range. The instrument consists of a 30 cm UV diffraction limited telescope followed by a two-grating, zero-dispersion spectroheliograph tuned to isolate the solar Lα emission line. During the flight, the instrument successfully obtained a series of images of the upper chromosphere with a limiting resolution of ∼ 0.33 arc sec. The resulting observations are the highest-resolution images of the solar atmosphere obtained from space to date. The flight demonstrated that sub-arc second ultraviolet images of the solar atmosphere are achievable with a high-quality, moderate-aperture space telescope and associated optics. Herein, we describe the payload and its in-flight performance. Title: Ultra-High Resolution Observations of the Upper Chromosphere: First Results From the NRL VAULT Sounding Rocket Payload Authors: Vourlidas, A.; Korendyke, C. M.; Dere, K. P.; Klimchuk, J. A. Bibcode: 2001AGUSM..SP61A03V Altcode: The Very high resolution Advanced ULtraviolet Telescope (VAULT) is a new spectroscopic imaging instrument. The instrument was launched on May 7, 1999 as a sounding rocket payload. The goal of the first VAULT flight was to obtain sub-arcsecond images of the Sun in the light of Lya (1216 Å). VAULT directly imaged an active region plage, fliaments and the fine structures in the supergranule boundaries and network with the unprecented spatial resolution of 0.33 arcseconds. We present the VAULT images and the first results from the comparison of the Lya data to observations from other instruments and in particular with a sequence of TRACE 171 Å images taken during the VAULT flight. Title: The Extreme Ultraviolet Imaging Spectrometer on Solar-B Authors: Mariska, J. T.; Brown, C. M.; Dere, K. P.; Doschek, G. A.; Korendyke, C. M.; Culhane, J. L.; Watanabe, T. Bibcode: 2001AGUSM..SH41A12M Altcode: Emission lines in the extreme ultraviolet spectral region provide a sensitive probe of the high-temperature plasma in the solar transition region and corona. Simultaneously achieving high spatial, spectral, and temporal resolution in this wavelength region has been challenging. We describe the design and capabilities of the Extreme Ultraviolet Imaging Spectrometer (EIS) planned for flight on the Japanese Solar-B satellite. EIS consists of a multilayer-coated off-axis telescope mirror and a multilayer-coated toroidal grating spectrometer. The telescope mirror forms a solar image on the spectrometer entrance slit assembly and the spectrometer forms stigmatic spectra of the solar region isolated by the 1024 arcsec high slit. The instrument includes thin-film aluminum filters to reject longer wavelength radiation and CCD detectors at the focal plane. Articulation of the primary mirror provides roughly 1600 arcsec of east-west coarse pointing freedom and 360 arcsec of fine east-west motion for rastering. Monochromatic images are formed either by rastering the solar image across a narrow entrance slit or by using a very wide slit. Half of each optic is coated to optimize reflectance at 19.5 nm, and the other half to optimize reflectance at 27.0 nm. Each wavelength range is imaged onto a separate CCD detector. The EIS spectral range contains emission lines formed over a temperature range from roughly 0.1 to 20 MK. Bright lines in the selected wavelength bands will yield precision measurements of line-of-sight velocities and nonthermal plasma motions. This spectral range also includes several pairs of density-sensitive lines. Title: High Resolution Observations of Solar Spectral Variability Near Mg II Measured by HRTS Authors: Morrill, J. S.; Dere, K. P.; Korendyke, C. M. Bibcode: 2001AGUSM..SP32B03M Altcode: The HRTS-9 rocket flight occurred on April 18, 1995 and made measurements of solar spectral variability near the Mg II h and k lines. These observations include high spatial and spectral resolution spectrograms as well as spectroheliograms in four FUV passbands and H-alpha. The spectrograms cover the wavelength range 2665 to 2885Å with a spectral resolution of .2Å and a spatial resolution of 1 arc-second along a 900 arc-second slit. The most prominent features in this spectral range include the strong Mg II h and k lines near 2800 Å, the Mg I and Si I Fraunhofer lines near 2850 and 2880Å, respectively, and the line-blanketed quasi-continuum region. During the HRTS-9 flight, spectrograms and spectroheliograms where obtained of the quiet sun, quiet limb, plage, and sunspots. In addition to instrumental corrections, we have recently applied an absolute intensity calibration to the HRTS-9 data derived from SUSIM/ATLAS-3 and SUSIM/UARS observations. The analysis of these calibrated data has focused on the spectral variability of the above surface features and how these observations impact solar irradiance variability. Specifically, we examine the contrast variation of the plage and sunspot compared to the quiet sun as well as contrast variation within the quiet sun. In this presentation we will discuss the details of the observed spectra and wavelength dependent contrast factors. This will include a comparison of our present results with earlier estimates of plage contrast in this wavelength region and a discussion of the fine structures observed at high spectral resolution. Title: Extreme-ultraviolet imaging spectrometer designed for the Japanese Solar-B satellite Authors: Culhane, J. L.; Korendyke, Clarence M.; Watanabe, Tetsuya; Doschek, George A. Bibcode: 2000SPIE.4139..294C Altcode: The Extreme-ultraviolet Imaging Spectrometer combines, for the first time, high spectral, spatial and temporal resolution in a satellite based, solar extreme ultraviolet instrument. The instrument optical design consists of a multilayer-coated off- axis paraboloid mirror telescope followed by a toroidal grating spectrometer. The instrument includes thin film aluminum filters to reject longer wavelength solar radiation and employs CCD detectors at the focal plane. The telescope mirror is articulated to allow sampling of a large fraction of the solar surface from a single spacecraft pointing position. Monochromatic images are obtained either by rastering the solar image across the narrow entrance slit or by using a wide slit or slot in place of the slit. Monochromatic images of the region centered on the slot are obtained in a single exposure. Half of each optic is coated to maximize reflectance at 195 angstrom; the other half is coated to maximize reflectance at 270 angstrom. The two EUV wavelength bands were selected to optimize spectroscopic plasma diagnostic capabilities. Particular care was taken to choose wavelength ranges with relatively bright emission lines to obtain precision line of sight and turbulent bulk plasma velocity measurements from observed line profiles. The EIS spectral range contains emission lines formed over a temperature range from approximately 105 - 107 K. The wavelength coverage also includes several density sensitive emission line pairs. These line pairs provide spatial resolution independent density diagnostics at nominal coronal temperatures and densities. Each wavelength band is imaged onto a separate CCD detector. The main EIS instrument characteristics are: wavelength bands -- 180 - 204 angstrom and 250 - 290 angstrom; spectral resolution -- 0.0223 angstrom/pixel (23 - 34 km/second-pixel); slit dimensions -- 4 slits: 1 X 1024 arc- seconds and 50 X 1024 arc-seconds with two positions unspecified as of this writing; fine raster range -- >6 arc-minutes on the sun; coarse raster range -- > 1600 arc- seconds on the sun; largest spatial field of view in a single exposure -- 50 X 1024 arc-seconds; nominal time resolution for active region velocity studies -- 3.4s. The Solar-B satellite is scheduled for launch in August 2005 into a nominal 600 km sun-synchronous orbit. Title: NASA Solar Terrestrial Relations Observatory (STEREO) mission heliospheric imager Authors: Socker, Dennis G.; Howard, Russell A.; Korendyke, Clarence M.; Simnett, George M.; Webb, David F. Bibcode: 2000SPIE.4139..284S Altcode: The NASA Solar Terrestrial Relations Observatory (STEREO) mission will place two spacecraft into solar orbits with sufficient separation to provide remote sensing instruments with a stereoscopic view of the heliosphere extending from the lower solar corona to beyond one astronomical unit. Analysis of the stereographs returned from the two spacecraft will allow solar physicists to infer the three-dimensional structure of small and large components of the corona. The Sun Earth Connection Coronal and Heliospheric Investigation (SECCHI) suite of remote sensing instruments includes a Heliospheric Imager (HI) to view the heliosphere in the interval from 12 to 215 solar radii. The HI will obtain the first stereographic images of coronal mass ejections in interplanetary space. Of particular interest is the subset of coronal mass ejections that propagate through the heliosphere and ultimately impact the earth. This paper presents the design concept for this new wide field coronagraph. Title: In-flight performance of the Very high Angular resolution ULtraviolet Telescope sounding rocket payload Authors: Korendyke, Clarence M.; Vourlidas, A.; Cook, John W.; Dere, Kenneth P.; Feldman, R.; Howard, Russell A.; Lilley, D. N.; Morrill, Jeff S.; Moses, J. Daniel; Moulton, Norman E.; Moye, Robert W.; Roberts, D. E.; Shepler, E. L.; Smith, J. K.; Socker, Dennis G.; Spears, T. R.; Waymire, R. S.; Brown, Wayne E.; Tarbell, Theodore D.; Berger, Tom; Handy, Brian N. Bibcode: 2000SPIE.4139..340K Altcode: The Very high Angular Resolution ULtraviolet Telescope experiment was successfully launched on May 7, 1999 on a Black Brant sounding rocket vehicle from White Sands Missile Range. The instrument consists of a 30 cm UV diffraction limited telescope followed by a double grating spectroheliograph tuned to isolate the solar Lyman (alpha) emission line. During the flight, the instrument successfully obtained a series of images of the upper chromosphere with a limiting resolution of approximately 0.33 arc-seconds. The resulting observations are the highest resolution images of the solar atmosphere obtained from space to date. The flight demonstrated that subarc-second ultraviolet images of the solar atmosphere are achievable with a high quality, moderate aperture space telescope and associated optics. Herein, we describe the payload and its in- flight performance. Title: Instrumentation for UV/EUV Astronomy and Solar Missions Authors: Fineschi, Silvano; Korendyke, Clarence M.; Siegmund, Oswald H.; Woodgate, Bruce E. Bibcode: 2000SPIE.4139.....F Altcode: No abstract at ADS Title: Solar UV Irradiance Variability Observed at High Spatial and Spectral Resolution by HRTS Authors: Morrill, J. S.; Dere, K. P.; Korendyke, C. M. Bibcode: 2000SPD....31.0128M Altcode: 2000BAAS...32..806M The HRTS-9 rocket flight occured on April 18, 1995 and was configured to study the sources of solar variablity by observing ultraviolet emission patterns near the Mg II h and k lines. These observations include high spatial and spectral resolution spectrograms as well as spectroheliograms in four FUV passbands and H-alpha. The spectrograms cover the wavelength range 2665 to 2885 Angstroms \ with a spectral resolution of .2 Angstroms \ and a spatial resolution of 1 arc-second along a 900 arc-second slit. Prominent spectral features in this wavelength range include the Mg II h and k lines near 2800 Angstroms, the strong Mg I and Si I Fraunhofer lines near 2850 and 2880 Angstroms, respectively, and the line-blanketed quasi-continuum region. HRTS-9 observations included the quiet sun, quiet limb, plage, and sunspots. The analysis of this data set has focused on the spatial intensity variability of the features as a function of wavelength with particular regard for how these will affect solar variability. Specifically, we examine the contrast variation of the plage and sunspot compared to the quiet sun as well as contrast variation within the quiet sun. The observed sunspot spectrum shows the characteristic decrease in the quasi-continuum, the non-reversed Mg II h and k line shapes as well as the enhancement in the Mg II h and k core emissions over that observed in the quiet sun. In this presentation we will discuss the wavelength dependent contrasts of the plage and quiet sun regions, the characteristics of the observed sunspot spectrum, and the implications on solar variability. Title: Search for Velocity Variations in Fe XIV 5304 A&ring Coronagraph Observations Near Activity Minimum Authors: Cook, J. W.; Socker, D. G.; Korendyke, C. M.; Howard, R. A.; Brueckner, G. E.; Karovska, M.; Wood, B. E. Bibcode: 2000AdSpR..25.1883C Altcode: The LASCO C1 coronagraph on the SOHO satellite observes the solar corona from 1.1 to 3.0 Ro, and contains a Fabry-Perot interferometer which can image the corona in the 1.8 million K Fe XIV green line. We designed an observing program with reduced spatial coverage and reduced profile coverage at only three wavelengths to study coronal heating in off-limb structures at high temporal resolution. We illustrate the observations from 31 March 1997 of a bright loop system above an active region off the northeast limb Title: Calibrated H I Lyman α Observations with TRACE Authors: Handy, B. N.; Tarbell, T. D.; Wolfson, C. J.; Korendyke, C. M.; Vourlidas, A. Bibcode: 1999SoPh..190..351H Altcode: Since shortly after launch in April 1998, the Transition Region and Coronal Explorer (TRACE) observatory has amassed a collection of H i Lα (1216 Å) observations of the Sun that have been not only of high spatial and temporal resolution, but also span a duration in time never before achieved. The Lα images produced by TRACE are, however, composed of not only the desired line emission, but also local ultraviolet continuum and longer wavelength contamination. This contamination has frustrated attempts to interpret TRACE observations in H i Lα. The Very Advanced Ultraviolet Telescope (VAULT) sounding rocket payload was launched from White Sands Missile range 7 May 1999 at 20:00 UT. The VAULT telescope for this flight was a dedicated H i Lα imaging spectroheliograph. We use TRACE observations in the 1216 Å and 1600 Å channels along with observations from the VAULT flight to develop a method for removing UV continuum and longer wavelength contamination from TRACE Lα images. Title: Concept Study Report: Extreme-Ultraviolet Imaging Spectrometer Solar-B Authors: Doschek, George A.; Brown, Charles M.; Davila, Joseph M.; Dere, Kenneth P.; Korendyke, Clarence M.; Mariska, John T.; Seely, John F. Bibcode: 1999STIN...0011153D Altcode: We propose a next generation Extreme-ultraviolet Imaging Spectrometer (EIS) that for the first time combines high spectral, spatial, and temporal resolution in a single solar spectroscopic instrument. The instrument consists of a multilayer-coated off-axis telescope mirror and a multilayer-coated grating spectrometer. The telescope mirror forms solar images on the spectrometer entrance slit assembly. The spectrometer forms stigmatic spectra of the solar region located at the slit. This region is selected by the articulated telescope mirror. Monochromatic images are obtained either by rastering the solar region across a narrow entrance slit, or by using a very wide slit (called a slot) in place of the slit. Monochromatic images of the region centered on the slot are obtained in a single exposure. Half of each optic is coated to maximize reflectance at 195 Angstroms; the other half to maximize reflectance at 270 Angstroms. The two Extreme Ultraviolet (EUV) wavelength bands have been selected to maximize spectral and dynamical and plasma diagnostic capabilities. Spectral lines are observed that are formed over a temperature range from about 0.1 MK to about 20 MK. The main EIS instrument characteristics are: wavelength bands - 180 to 204 Angstroms; 250 to 290 Angstroms; spectral resolution - 0.0223 Angstroms/pixel (34.3km/s at 195 Angstroms and 23.6 km/s at 284 Angstroms); slit dimensions - 4 slits, two currently specified dimensions are 1" x 1024" and 50" x 1024" (the slot); largest spatial field of view in a single exposure - 50" x 1024"; highest time resolution for active region velocity studies - 4.4 s. Title: LASCO/SOHO Observations of Dust in the Outer Solar Corona Authors: Kimura, H.; Mann, I.; Goldstein, B.; Korendyke, C.; Howard, R. Bibcode: 1999DPS....31.5501K Altcode: The solar F-corona emission is comprised of solar radiation scattered by dust particles and thermal radiation emitted from near-solar dust particles. The visible brightness is mainly produced by scattering at medium scattering angles from particles near the Sun and by enhanced forward scattering from particles near the observer. The infrared brightness originates from the thermal emission from hot particles near the Sun. Studies of the F-corona are usually limited by the influence of atmospheric stray light and by difficulties of the separation of the K-corona, produced by sunlight scattered at electrons. The K-corona decreases steeply with increasing elongation and has a smaller contribution to the outer coronal brightness. This outer corona is observed from the SOHO satellite where the lack of atmospheric stray light and an optimized suppression of instrumental stray light in the LASCO coronagraph allow for the detection of the coronal brightness as far out as about 30 solar radii from the center of the Sun. These observations yield the opportunity to study the properties of interplanetary dust in the inner solar system. We will present preliminary results from the analysis of the data from the LASCO C3 coronagraph at distances from 10 to 30 solar radii from the center of the Sun in 3 wavelength intervals between 0.4 and 1.1 micron. We compare the data to brightness calculations in order to discuss the distribution of dust grains in the inner solar system. The Solar Heliospheric Observatory, SOHO, is a joint scientific space mission developed by ESA and NASA. The Large Angle Spectrometric Coronagraph (LASCO) was developed and is operated jointly by the Naval Research Laboratory (USA), the Max-Planck-Institut fur Aeronomie (Germany), the Laboratoire d'Astronomie Spatiale (France) and the University of Birmingham (UK). Title: LASCO/SOHO observations of dust in the outer solar corona. Authors: Kimura, H.; Mann, I.; Goldstein, B.; Korendyke, C.; Howard, R. Bibcode: 1999BAAS...31.1159K Altcode: No abstract at ADS Title: HRTS Observations of Solar Fine Scale Structures in the Near-UV Authors: Morrill, J. S.; Dere, K. P.; Korendyke, C. M. Bibcode: 1999AAS...194.9311M Altcode: 1999BAAS...31..990M The NRL High Resolution Telescope and Spectrograph (HRTS) obtains ultraviolet spectra, ultraviolet spectroheliograms and H alpha spectroheliograms at a spatial resolution of about 1 arc-second along a 900 arc-second slit. The HRTS-9 rocket flew on April 18, 1995 during the declining phase of the solar cycle. The HRTS-9 instrument and observing program were tailored to observe emission patterns inthe ultraviolet for the purpose of studying solar variability. Observation targets included the quiet sun, active regions and the quiet limb. The wavelength range of HRTS-9 spectrograph was from 275 nm to 290 nm. Some of the prominent spectral features in this wavelength range are the Mg II h and k lines at 280 nm, the strong Mg I Fraunhofer line at 285 nm, and the continuum. The ultraviolet spectroheliograph obtained images of a portion of the sun at wavelengths corresponding to a range of temperatures: 1550 (C IV), 1540 (Si I), 1560 (C I), and 1600 (continuum). The primary goal of the HRTS-9 rocket program was to examine the origin of the total solar variability in the intensity variations of solar structures in the near ultraviolet on a variety of spatial scales. The HRTS-9 data reveals the fine structure of the quiet sun, plage, and sun spots in the near ultraviolet. In addition, active region contrast factors are determined for comparison with modes of full disk ultraviolet variability based on SUSIM and SOLTICE observations from UARS. Title: Solar Polar Imager Authors: Moses, D.; Dere, K. P.; Howard, R. A.; Korendyke, C. M.; Socker, D. G.; Wang, Y. -M.; Goldstein, B. E.; Liewer, P. E. Bibcode: 1999AAS...194.7613M Altcode: 1999BAAS...31..958M Observation of the global coronal and magnetic field structure of the Sun requires coronal imaging and magnetograms from a perspective out of the ecliptic. While the upcoming Solar Terrestrial Relations Observatory (STEREO) mission will provide a great advance in the understanding of the three-dimensional structure of the corona and interplanetary medium, the orientation of the Sun's large scale magnetic axis of symmetry with the STEREO spacecraft separation defines the limits of this mission. The global structure of the streamer belts, polar coronal holes and coronal plumes all reflect the symmetry of the large scale solar magnetic field. Observations of Coronal Mass Ejections (CMEs) from the LASCO and EIT instruments on the Solar and Heliospheric Observatory (SOHO) indicate the need for synoptic coronal imaging out of the ecliptic (Solar Polar Imager), as well as in stereo pairs in the ecliptic (STEREO), for advancement in the understanding of the origins and consequences of CMEs. The SOHO MDI has shown the need for observations of the evolution of the polar magnetic fields and convection patterns to understand the generation and transport of the solar magnetic fields. Finally, the Ulysses mission has shown the need for polar coronal imaging and magnetograms for understanding the source of the solar wind. Ulysses has demonstrated the need for on-board in situ particles and fields instruments as a link to the remote sensing observations. Lightweight and compact instrumentation for these observations has already been demonstrated technically. An orbital mission involving a Jupiter assist such as Ulysses is also technically demonstrated, although the duration of the polar observations is limited to the point of degrading the studies of solar cycle evolution. An orbital mission involving a circularized polar orbit is possible with the use of solar-sail propulsion, but this involves technology that has yet to be demonstrated. Title: Extension of the Polar Coronal Hole Boundary into Interplanetary space Authors: Woo, Richard; Habbal, Shadia Rifai; Howard, Russell A.; Korendyke, Clarence M. Bibcode: 1999ApJ...513..961W Altcode: White-light measurements made by the SOHO LASCO C2 and C3 coronagraphs and the Mk III Mauna Loa K-coronameter, ranging from 1.15 to 30 Rsolar, have been combined with Kitt Peak daily He I 1083 nm coronal hole maps, and full Sun Yohkoh soft X-ray images, to show that the boundaries of polar coronal holes, as determined by measurements of path-integrated density, extend approximately radially into interplanetary space. These results are in contrast to the long-standing view that the boundaries of polar coronal holes diverge significantly beyond radial, evolving around the edges of streamers. The combined observations also show that the corona is dominated by raylike structures as small as a few degrees in angular size with respect to Sun center, originating from both coronal holes and the quiet Sun. This analysis provides further support for results originally derived from radio occultation measurements, namely, that the coronal density projects itself almost radially from the Sun into the outer corona, implying that open field lines abound in the quiet Sun from which the fast wind can alsooriginate. Title: Corrals, hubcaps, and crystal balls: some new designs for very-wide-angle visible-light heliospheric imagers Authors: Buffington, Andrew; Hick, P. P.; Jackson, Bernard V.; Korendyke, Clarence M. Bibcode: 1998SPIE.3442...77B Altcode: Emerging techniques allow instruments to view very large sky areas, a hemisphere or more, in visible light. In space, such wide-angle coverage enables observation of heliospheric features form close to the Sun to well beyond Earth. Observations from deep-space missions such as Solar Probe, Stereo, and Solar Polar Sail, coupled with observations near Earth, permit 3D reconstruction of solar mass ejections and co-rotating structures, discovery and study of new comets and asteroids, and detailed measurements of brightness variations in the zodiacal cloud. Typical heliospheric features have 1 percent or less of ambient brightness, so visible-light cameras must deliver < 0.1 percent photometry and be well protected from stray background light. When more than a hemisphere of viewing area is free of bright background-light sources, we have shown that corral-like structures with several vane-like walls reduces background light illuminating to wide-angle optical system by up to ten orders of magnitude. The optical system itself typically provides another five orders of surface-brightness reduction. With CCDs as the light-detection device, images of point-like sources must cover typically 100 pixels to average down sub-pixel response gradients and provide the above 0.1 percent photometry. With present-day CCDs this requires images of order 1 degree in angular size. Tolerating such large images in turn enables wide-angle sky coverage using simple reflecting and refracting optical systems such as convex spherical reflectors, toroids and thick lenses. We show that combining these with light- reducing corrals yields practical, light-weight instruments suitable for inclusion on deep-space probes. Title: Search for Brightness Variations in Fe XIV Coronagraph Observations of the Quiescent Solar Corona Authors: Wood, B. E.; Karovska, M.; Cook, J. W.; Brueckner, G. E.; Howard, R. A.; Korendyke, C. M.; Socker, D. G. Bibcode: 1998ApJ...505..432W Altcode: We use Fe XIV 5303 Å green line images obtained by the Large Angle Spectrometric Coronagraph (LASCO) on board SOHO to search for variability in the quiescent solar corona in the shortest observable timescales. The observing program obtained Fe XIV images of a small area of the inner corona every 2 minutes over a period of 1 hr. We present results from two executions of this program taken several months apart. The most obvious variability observed in the two sequences is in the form of quasi-steady brightening on timescales of at least an hour. Of particular interest are two compact loops that are observed to vary significantly during the course of the observations. Superposed on the long-term brightening in these loops are statistically significant variations on timescales of about 30 minutes. In both loops, the overall brightening is greatest at the apparent loop tops, where the intensity increases by at least 25%. In one loop there appears to be a flow up one of the legs of the loop. We place these observations in context with earlier observations of coronal variability, and we discuss the energy requirements for the observed brightening. Emission measures computed from Fe XIV intensities measured within the two brightening loops are over an order of magnitude lower than those typically found for active regions on the solar disk, which suggests significantly lower average densities. For one of the loops, we measure densities in the range ne = (5.0-7.4) × 108 cm-3. Lower than average densities are expected for the two loops, given that they reach more than 1 pressure scale height above the solar limb. Title: Missions to the sun II : 22-23 July 1998, San Diego, California Authors: Korendyke, Clarence M. Bibcode: 1998SPIE.3442.....K Altcode: No abstract at ADS Title: White-Light Coronal Mass Ejections: A New Perspective from LASCO Authors: St. Cyr, O. C.; Howard, R. A.; Simnett, G. M.; Gurman, J. B.; Plunkett, S. P.; Sheeley, N. R.; Schwenn, R.; Koomen, M. J.; Brueckner, G. E.; Michels, D. J.; Andrews, M.; Biesecker, D. A.; Cook, J.; Dere, K. P.; Duffin, R.; Einfalt, E.; Korendyke, C. M.; Lamy, P. L.; Lewis, D.; Llebaria, A.; Lyons, M.; Moses, J. D.; Moulton, N. E.; Newmark, J.; Paswaters, S. E.; Podlipnik, B.; Rich, N.; Schenk, K. M.; Socker, D. G.; Stezelberger, S. T.; Tappin, S. J.; Thompson, B.; Wang, D. Bibcode: 1997ESASP.415..103S Altcode: 1997cpsh.conf..103S No abstract at ADS Title: Origins of the Slow and the Ubiquitous Fast Solar Wind Authors: Habbal, S. R.; Woo, R.; Fineschi, S.; O'Neal, R.; Kohl, J.; Noci, G.; Korendyke, C. Bibcode: 1997ApJ...489L.103H Altcode: 1997astro.ph..9021H We present in this Letter the first coordinated radio occultation measurements and ultraviolet observations of the inner corona below 5.5Rs, obtained during the Galileo solar conjunction in 1997 January, to establish the origin of the slow solar wind. Limits on the flow speed are derived from the Doppler dimming of the resonantly scattered component of the oxygen 1032 and 1037.6 Å lines as measured with the ultraviolet coronagraph spectrometer (UVCS) on the Solar and Heliospheric Observatory (SOHO). White light images of the corona from the large-angle spectroscopic coronagraph (LASCO) on SOHO taken simultaneously are used to place the Doppler radio scintillation and ultraviolet measurements in the context of coronal structures. These combined observations provide the first direct confirmation of the view recently proposed by Woo & Martin that the slow solar wind is associated with the axes, also known as stalks, of streamers. Furthermore, the ultraviolet observations also show how the fast solar wind is ubiquitous in the inner corona and that a velocity shear between the fast and slow solar wind develops along the streamer stalks. Title: LASCO Observations of Disconnected Magnetic Structures Out to Beyond 28 Solar Radii During Coronal Mass Ejections Authors: Simnett, G. M.; Tappin, S. J.; Plunkett, S. P.; Bedford, D. K.; Eyles, C. J.; St. Cyr, O. C.; Howard, R. A.; Brueckner, G. E.; Michels, D. J.; Moses, J. D.; Socker, D.; Dere, K. P.; Korendyke, C. M.; Paswaters, S. E.; Wang, D.; Schwenn, R.; Lamy, P.; Llebaria, A.; Bout, M. V. Bibcode: 1997SoPh..175..685S Altcode: Two coronal mass ejections have been well observed by the LASCO coronagraphs to move out into the interplanetary medium as disconnected plasmoids. The first, on July 28, 1996, left the Sun above the west limb around 18:00 UT. As it moved out, a bright V-shaped structure was visible in the C2 coronagraph which moved into the field-of-view of C3 and could be observed out to beyond 28 solar radii. The derived average velocity in the plane of the sky was 110 ± 5 km s-1 out to 5 solar radii, and above 15 solar radii the velocity was 269 ± 10 km s-1. Thus there is evidence of some acceleration around 6 solar radii. The second event occurred on November 5, 1996 and left the west limb around 04:00 UT. The event had an average velocity in the plane of the sky of ∼54 km s-1 below 4 R⊙, and it accelerated rapidly around 5 R⊙ up to 310 ± 10 km s-1. In both events the rising plasmoid is connected back to the Sun by a straight, bright ray, which is probably a signature of a neutral sheet. In the November event there is evidence for multiple plasmoid ejections. The acceleration of the plasmoids around a projected altitude of 5 solar radii is probably a manifestation of the source surface of the solar wind. Title: First View of the Extended Green-Line Emission Corona At Solar Activity Minimum Using the Lasco-C1 Coronagraph on SOHO Authors: Schwenn, R.; Inhester, B.; Plunkett, S. P.; Epple, A.; Podlipnik, B.; Bedford, D. K.; Eyles, C. J.; Simnett, G. M.; Tappin, S. J.; Bout, M. V.; Lamy, P. L.; Llebaria, A.; Brueckner, G. E.; Dere, K. P.; Howard, R. A.; Koomen, M. J.; Korendyke, C. M.; Michels, D. J.; Moses, J. D.; Moulton, N. E.; Paswaters, S. E.; Socker, D. G.; St. Cyr, O. C.; Wang, D. Bibcode: 1997SoPh..175..667S Altcode: The newly developed C1 coronagraph as part of the Large-Angle Spectroscopic Coronagraph (LASCO) on board the SOHO spacecraft has been operating since January 29, 1996. We present observations obtained in the first three months of operation. The green-line emission corona can be made visible throughout the instrument's full field of view, i.e., from 1.1 R⊙ out to 3.2 R⊙ (measured from Sun center). Quantitative evaluations based on calibrations cannot yet be performed, but some basic signatures show up even now: (1) There are often bright and apparently closed loop systems centered at latitudes of 30° to 45° in both hemispheres. Their helmet-like extensions are bent towards the equatorial plane. Farther out, they merge into one large equatorial `streamer sheet' clearly discernible out to 32 R⊙. (2) At mid latitudes a more diffuse pattern is usually visible, well separated from the high-latitude loops and with very pronounced variability. (3) All high-latitude structures remain stable on time scales of several days, and no signature of transient disruption of high-latitude streamers was observed in these early data. (4) Within the first 4 months of observation, only one single `fast' feature was observed moving outward at a speed of 70 km s-1 close to the equator. Faster events may have escaped attention because of data gaps. (5) The centers of high-latitude loops are usually found at the positions of magnetic neutral lines in photospheric magnetograms. The large-scale streamer structure follows the magnetic pattern fairly precisely. Based on our observations we conclude that the shape and stability of the heliospheric current sheet at solar activity minimum are probably due to high-latitude streamers rather than to the near-equatorial activity belt. Title: The Relationship of Green-Line Transients to White-Light Coronal Mass Ejections Authors: Plunkett, S. P.; Brueckner, G. E.; Dere, K. P.; Howard, R. A.; Koomen, M. J.; Korendyke, C. M.; Michels, D. J.; Moses, J. D.; Moulton, N. E.; Paswaters, S. E.; St. Cyr, O. C.; Socker, D. G.; Wang, D.; Simnett, G. M.; Bedford, D. K.; Biesecker, D. A.; Eyles, C. J.; Tappin, S. J.; Schwenn, R.; Lamy, P. L.; Llebaria, A. Bibcode: 1997SoPh..175..699P Altcode: We report observations by the Large Angle Spectrometric Coronagraph (LASCO) on the SOHO spacecraft of three coronal green-line transients that could be clearly associated with coronal mass ejections (CMEs) detected in Thomson-scattered white light. Two of these events, with speeds >25 km s-1, may be classified as `whip-like' transients. They are associated with the core of the white-light CMEs, identified with erupting prominence material, rather than with the leading edge of the CMEs. The third green-line transient has a markedly different appearance and is more gradual than the other two, with a projected outward speed <10 km s-1. This event corresponds to the leading edge of a `streamer blowout' type of CME. A dark void is left behind in the emission-line corona following each of the fast eruptions. Both fast emission-line transients start off as a loop structure rising up from close to the solar surface. We suggest that the driving mechanism for these events may be the emergence of new bipolar magnetic regions on the surface of the Sun, which destabilize the ambient corona and cause an eruption. The possible relationship of these events to recent X-ray observations of CMEs is briefly discussed. Title: MHD Interpretation of LASCO Observations of a Coronal Mass Ejection as a Disconnected Magnetic Structure Authors: Wu, S. T.; Guo, W. P.; Andrews, M. D.; Brueckner, G. E.; Howard, R. A.; Koomen, M. J.; Korendyke, C. M.; Michels, D. J.; Moses, J. D.; Socker, D. G.; Dere, K. P.; Lamy, P. L.; Llebaria, A.; Bout, M. V.; Schwenn, R.; Simnett, G. M.; Bedford, D. K.; Eyles, C. J. Bibcode: 1997SoPh..175..719W Altcode: We present a qualitative and quantitative comparison of a single coronal mass ejection (CME) as observed by LASCO (July 28-29, 1996) with the results of a three-dimensional axisymmetric time-dependent magnetohydrodynamic model of a flux rope interacting with a helmet streamer. The particular CME considered was selected based on the appearance of a distinct `tear-drop' shape visible in animations generated from both the data and the model. Title: EIT and LASCO Observations of the Initiation of a Coronal Mass Ejection Authors: Dere, K. P.; Brueckner, G. E.; Howard, R. A.; Koomen, M. J.; Korendyke, C. M.; Kreplin, R. W.; Michels, D. J.; Moses, J. D.; Moulton, N. E.; Socker, D. G.; St. Cyr, O. C.; Delaboudinière, J. P.; Artzner, G. E.; Brunaud, J.; Gabriel, A. H.; Hochedez, J. F.; Millier, F.; Song, X. Y.; Chauvineau, J. P.; Marioge, J. P.; Defise, J. M.; Jamar, C.; Rochus, P.; Catura, R. C.; Lemen, J. R.; Gurman, J. B.; Neupert, W.; Clette, F.; Cugnon, P.; Van Dessel, E. L.; Lamy, P. L.; Llebaria, A.; Schwenn, R.; Simnett, G. M. Bibcode: 1997SoPh..175..601D Altcode: We present the first observations of the initiation of a coronal mass ejection (CME) seen on the disk of the Sun. Observations with the EIT experiment on SOHO show that the CME began in a small volume and was initially associated with slow motions of prominence material and a small brightening at one end of the prominence. Shortly afterward, the prominence was accelerated to about 100 km s-1 and was preceded by a bright loop-like structure, which surrounded an emission void, that traveled out into the corona at a velocity of 200-400 km s-1. These three components, the prominence, the dark void, and the bright loops are typical of CMEs when seen at distance in the corona and here are shown to be present at the earliest stages of the CME. The event was later observed to traverse the LASCO coronagraphs fields of view from 1.1 to 30 R⊙. Of particular interest is the fact that this large-scale event, spanning as much as 70 deg in latitude, originated in a volume with dimensions of roughly 35" (2.5 x 104 km). Further, a disturbance that propagated across the disk and a chain of activity near the limb may also be associated with this event as well as a considerable degree of activity near the west limb. Title: Origin and Evolution of Coronal Streamer Structure During the 1996 Minimum Activity Phase Authors: Wang, Y. -M.; Sheeley, N. R., Jr.; Howard, R. A.; Kraemer, J. R.; Rich, N. B.; Andrews, M. D.; Brueckner, G. E.; Dere, K. P.; Koomen, M. J.; Korendyke, C. M.; Michels, D. J.; Moses, J. D.; Paswaters, S. E.; Socker, D. G.; Wang, D.; Lamy, P. L.; Llebaria, A.; Vibert, D.; Schwenn, R.; Simnett, G. M. Bibcode: 1997ApJ...485..875W Altcode: We employ coronal extrapolations of solar magnetograph data to interpret observations of the white-light streamer structure made with the LASCO coronagraph in 1996. The topological appearance of the streamer belt during the present minimum activity phase is well described by a model in which the Thomson-scattering electrons are concentrated around a single, warped current sheet encircling the Sun. Projection effects give rise to bright, jet-like structures or spikes whenever the current sheet is viewed edge-on multiple spikes are seen if the current sheet is sufficiently wavy. The extreme narrowness of these features in polarized images indicates that the scattering layer is at most a few degrees wide. We model the evolution of the streamer belt from 1996 April to 1996 September and show that the effect of photospheric activity on the streamer belt topology depends not just on the strength of the erupted magnetic flux, but also on its longitudinal phase relative to the background field. Using flux transport simulations, we also demonstrate how the streamer belt would evolve during a prolonged absence of activity. Title: The Green Line Corona and Its Relation to the Photospheric Magnetic Field Authors: Wang, Y. -M.; Sheeley, N. R., Jr.; Hawley, S. H.; Kraemer, J. R.; Brueckner, G. E.; Howard, R. A.; Korendyke, C. M.; Michels, D. J.; Moulton, N. E.; Socker, D. G.; Schwenn, R. Bibcode: 1997ApJ...485..419W Altcode: Images of the green line corona made with the LASCO C1 coronagraph on SOHO are analyzed by applying current-free extrapolations to the observed photospheric field. The Fe XIV λ5303 emission is shown to be closely related to the underlying photospheric field strength. By modeling the observed intensity patterns as a function of latitude and height above the solar limb, we derive an approximate scaling law of the form nfoot ~ <Bfoot>0.9, where nfoot is the density of the green line-emitting plasma and <Bfoot> is the average field strength at the footprints of the coronal loop. The observed high-latitude enhancements in the green line corona are attributed to the poleward concentration of the large-scale photospheric field. The strongest such enhancements occur where the high-latitude unipolar fields become reconnected to active region flux at lower latitudes; the global emission pattern rotates quasi-rigidly at the rate of the dominant active region complex. The validity of the current-free approximation is assessed by comparing the topology of the observed and simulated green line structures. Title: Measurements of Flow Speeds in the Corona Between 2 and 30 R Authors: Sheeley, N. R.; Wang, Y. -M.; Hawley, S. H.; Brueckner, G. E.; Dere, K. P.; Howard, R. A.; Koomen, M. J.; Korendyke, C. M.; Michels, D. J.; Paswaters, S. E.; Socker, D. G.; St. Cyr, O. C.; Wang, D.; Lamy, P. L.; Llebaria, A.; Schwenn, R.; Simnett, G. M.; Plunkett, S.; Biesecker, D. A. Bibcode: 1997ApJ...484..472S Altcode: Time-lapse sequences of white-light images, obtained during sunspot minimum conditions in 1996 by the Large Angle Spectrometric Coronagraph on the Solar and Heliospheric Observatory, give the impression of a continuous outflow of material in the streamer belt, as if we were observing Thomson scattering from inhomogeneities in the solar wind. Pursuing this idea, we have tracked the birth and outflow of 50-100 of the most prominent moving coronal features and find that:

1. They originate about 3-4 R from Sun center as radially elongated structures above the cusps of helmet streamers. Their initial sizes are about 1 R in the radial direction and 0.1 R in the transverse direction.

2. They move radially outward, maintaining constant angular spans and increasing their lengths in rough accord with their speeds, which typically double from 150 km s-1 near 5 R to 300 km s-1 near 25 R.

3. Their individual speed profiles v(r) cluster around a nearly parabolic path characterized by a constant acceleration of about 4 m s-2 through most of the 30 R field of view. This profile is consistent with an isothermal solar wind expansion at a temperature of about 1.1 MK and a sonic point near 5 R.

Based on their relatively small initial sizes, low intensities, radial motions, slow but increasing speeds, and location in the streamer belt, we conclude that these moving features are passively tracing the outflow of the slow solar wind. Title: Using LASCO Observations to Infer Solar Wind Flow Near the Sun Authors: Sheeley, N. R., Jr.; Brueckner, G. E.; Dere, K. P.; Howard, R. A.; Korendyke, C. M.; Michels, D. J.; Socker, D. G.; Koomen, M. J.; Paswaters, S. E.; Wang, D.; Lamy, P. L.; Llebaria, A.; Schwenn, R.; St Cyr, O. C.; Simnett, G. M.; Plunkett, S.; Biesecker, D. A. Bibcode: 1997SPD....28.0301S Altcode: 1997BAAS...29..907S We have continued to track individual coronal features as they become detached from helmet streamers and move outward from the Sun. The composite speed profile for 50-100 features has a parabolic shape with a constant acceleration of about 4 m/s(2) over the 2-30 R field of view. This well-determined speed profile contrasts strongly with the nearly uniform scatterplot obtained for about 50 nominal coronal mass ejections (CMEs), and suggests that these detached bits of coronal ``debris'' are passively tracing the speed of the slow solar wind. We have also begun the more difficult task of tracking outflow along polar plumes and will summarize these results as of June 1997. Title: Search for Velocity Signatures of Energy Release in Fine Scale Coronal Features Authors: Cook, J. W.; Socker, D. G.; Korendyke, C. M.; Howard, R. A.; Karovska, M. Bibcode: 1997SPD....28.0119C Altcode: 1997BAAS...29..882C The Large Angle Spectrometric Coronagraph (LASCO) on the SOHO satellite consists of three individual coronagraphs with nested fields of view. The innermost C1 coronagraph observes the solar corona from 1.1 to 3.0 R_⊙, and contains a Fabry Perot interferometer which can image the corona in the 1.8 million K Fe XIV emission line at 5303 Angstroms with 0.7 Angstroms resolution. We designed an observing program with reduced spatial coverage and reduced profile coverage at only three wavelengths (line center and the half power points of the thermal plus instrumental profile) in order to increase the observing cadence. From these observations we can construct maps of the observed field in integrated line intensity, doppler velocity shift, and nonthermal broadening. We can thus search for signatures of coronal heating such as transient brightenings, bulk velocity flows, or nonthermal turbulent line broadening at spatial scales down to 11 arc sec (two CCD pixels), with temporal resolution of 4 minutes. We have run this program several times so far, and will report on early results. Title: Dynamical Evolution of a Coronal Mass Ejection (CME) to Magnetic Cloud: A Preliminary Analysis of the January 6-10, 1997 CME Observed by LASCO/SOHO Authors: Wu, S. T.; Guo, W. P.; Michels, D. J.; Andrews, M. D.; Brueckner, G. E.; Howard, R. A.; Koomen, M. J.; Korendyke, C. M.; Moses, J. D.; Socker, D. G.; Dere, K. P.; Bougeret, Jean-Louis; Lamy, P. L.; Schwenn, R.; Simnett, G. M. Bibcode: 1997ESASP.404..739W Altcode: 1997cswn.conf..739W No abstract at ADS Title: EIT and LASCO Observations of the Initiation of a Coronal Mass Ejection Authors: Dere, K. P.; Brueckner, G. E.; Howard, R. A.; Koomen, M. J.; Korendyke, C. M.; Michels, D. J.; Moses, J. D.; Moulton, N. E.; Socker, D. G.; Delaboudiniere, J. P.; Hochedez, J. F.; Lamy, P. L.; Schwenn, R.; Simnett, G. M.; Defise, J. M.; Catura, R. C. Bibcode: 1997IAUJD..19E..18D Altcode: We present the first observations of the initiation of a corona mass ejection (CME) seen on the disk of the Sun. Observations with the EIT and LASCO experiments on SOHO show that the CME starts in a small volume and is associated with slow motions of prominence material. At about the same time, a shock wave is created that travels out into the corona at a velocity of 400 km s^{-1} ahead of an eruptive prominence. This shock wave is clearly the event that is later seen as a classical CME when observed in the coronagraph above 1.5 solar radii. Although the CME clearly starts in a small region, a chain of activity near the limb may also be associated with this event. Title: The quiescent corona and slow solar wind Authors: Noci, G.; Kohl, J. L.; Antonucci, E.; Tondello, G.; Huber, M. C. E.; Fineschi, S.; Gardner, L. D.; Korendyke, C. M.; Nicolosi, P.; Romoli, M.; Spadaro, D.; Maccari, L.; Raymond, J. C.; Siegmund, O. H. W.; Benna, C.; Ciaravella, A.; Giordano, S.; Michels, J.; Modigliani, A.; Naletto, G.; Panasyuk, A.; Pernechele, C.; Poletto, G.; Smith, P. L.; Strachan, L. Bibcode: 1997ESASP.404...75N Altcode: 1997cswn.conf...75N; 1997soho....5...75N No abstract at ADS Title: Enhancing the Spatial Resolution of Solar Coronagraph Observations Using Dynamic Imaging Authors: Zaccheo, T. S.; Karovska, M.; Cook, J. W.; Howard, R. A.; Brueckner, G. E.; Korendyke, C. M.; Schwenn, R. Bibcode: 1996ApJ...471.1058Z Altcode: The Large Angle Spectrometric Coronagraph (LASCO) Cl coronagraph on board the Solar and Heliospheric Observatory (SOHO) is designed to image the corona from 1.1 to 3.0 Rsun. The resolution of C1 is defined by the size of its CCD pixels, which correspond to 5".6, and not by the diffraction limit of the optical system, which may be as small as 3". The resolution of Cl can be improved using the technique of "dynamic imaging" the process of acquiring successive images of the same scene using sub- pixel displacements of the steerable primary mirror. We developed a technique we call the fractional pixel restoration (F PR) algorithm that utilizes these observations to construct an image with improved resolution. Simulations were used to test this algorithm and to explore its limitations. We also applied the direct co-addition and FPR algorithms to laboratory preffight images of a wire mesh grid. These results show that the resolution of the C1 coronagraph can be significantly enhanced, even in the presence of noise and modest differences between successive images. In some cases, the results can even reach the diffraction limit of the telescope. Title: LASCO spectrometric Lyot coronagraph tunable passband filter Authors: Socker, Dennis G.; Brueckner, Guenter E.; Korendyke, Clarence M.; Lilley, D. N.; Steenson, James H.; Kohn, Preston M.; Lyons, Gail M.; Owens, Michael L.; Moulton, Norman E.; Moye, Robert W.; Schwenn, Rainer; Hemmerich, P. Bibcode: 1996SPIE.2804..126S Altcode: Spectrometric and spectropolarimetric aspects of the Lyot coronagraph flown aboard the ESA/NASA SOlar Heliospheric Observatory (SOHO) are presented. The coronagraph is one of the three channels comprising the LASCO coronagraph and the only channel with spectroradiometric capabilities. Among the primary science objectives assigned to the Lyot coronagraph are the determination of the mechanisms responsible for the acceleration of the solar wind and the heating of the corona. Spectrometric and spectropolarimetric coronal observations made with the Lyot coronagraph are used in support of these and other objectives. We describe the Lyot instrument design from the imaging coronal spectrometer perspective. The rationale for use of a tunable Fabry-Perot interferometer as the spectral resolving element is outlined. The relationships between spectral resolving power, interferometer diameter, telescope entrance stop diameter and coronal field of view as it applies to LASCO is reviewed. Performance requirements imposed on the interferometer by the coronal source and the science objectives are described. The optical, mechanical, electronic and semi-automated control designs as well as the interferometer modes of operation are summarized. The actual flight model Fabry-Perot interferometer performance allows the instrument to operate with high luminosity and with finesse values high enough to provide approximately optimal passband widths and reasonable tunable ranges about useful spectral features. We conclude with some early results indicative of the flight performance of the instrument. Title: STEREO: a solar terrestrial event observer mission concept Authors: Socker, Dennis G.; Antiochos, S. K.; Brueckner, Guenter E.; Cook, John W.; Dere, Kenneth P.; Howard, Russell A.; Karpen, J. T.; Klimchuk, J. A.; Korendyke, Clarence M.; Michels, Donald J.; Moses, J. Daniel; Prinz, Dianne K.; Sheely, N. R.; Wu, Shi T.; Buffington, Andrew; Jackson, Bernard V.; Labonte, Barry; Lamy, Philippe L.; Rosenbauer, H.; Schwenn, Rainer; Burlaga, L.; Davila, Joseph M.; Davis, John M.; Goldstein, Barry; Harris, H.; Liewer, Paulett C.; Neugebauer, Marcia; Hildner, E.; Pizzo, Victor J.; Moulton, Norman E.; Linker, J. A.; Mikic, Z. Bibcode: 1996SPIE.2804...50S Altcode: A STEREO mission concept requiring only a single new spacecraft has been proposed. The mission would place the new spacecraft in a heliocentric orbit and well off the Sun- Earth line, where it can simultaneously view both the solar source of heliospheric disturbances and their propagation through the heliosphere all the way to the earth. Joint observations, utilizing the new spacecraft and existing solar spacecraft in earth orbit or L1 orbit would provide a stereographic data set. The new and unique aspect of this mission lies in the vantage point of the new spacecraft, which is far enough from Sun-Earth line to allow an entirely new way of studying the structure of the solar corona, the heliosphere and solar-terrestrial interactions. The mission science objectives have been selected to take maximum advantage of this new vantage point. They fall into two classes: those possible with the new spacecraft alone and those possible with joint measurements using the new and existing spacecraft. The instrument complement on the new spacecraft supporting the mission science objectives includes a soft x-ray imager, a coronagraph and a sun-earth imager. Telemetry rate appears to be the main performance determinant. The spacecraft could be launched with the new Med-Lite system. Title: Next-generation EUV imaging spectrometer for solar flare observations Authors: Moses, J. Daniel; Brueckner, Guenter E.; Dere, Kenneth P.; Korendyke, Clarence M.; Moulton, Norman E.; Prinz, Dianne K.; Seely, John F.; Socker, Dennis G.; Bruner, Marilyn E.; Lemen, James R. Bibcode: 1996SPIE.2804..260M Altcode: The Naval Research Laboratory Skylab SO82A slitless spectrograph provided solar flare observations that have never been equaled in diagnostic capabilities for interpreting thermal flare physics. Improvements in detector technology, optics and optical coating technology, and almost two decades of analysis of SO82A data can be combined with the basic concept of an EUV objective grating spectrograph to build an instrument to address many of the remaining mysteries of solar flares. This next generation instrument incorporates two sets of two identical, orthogonally mounted slitless spectrographic Cassegrain telescopes. Each telescope consists of a multilayer coated, Wadsworth mount objective grating and multilayer coated spherical secondary mirror; a backside illuminated CCD detector is installed at the focal plane. The orthogonal mounting changes the dispersion direction by 90 degrees on the disk image; processing on the two resulting images allows recovery of the undispersed disk image and spectral line profiles. The resulting instrument will obtain high time cadence, spectrally-dispersed images with improved spatial resolution, dynamic range, signal-to-noise ratio, and velocity discrimination. Title: LASCO Observations of the 03Feb96 Streamer Blow-out Authors: Andrews, M. D.; Korendyke, C. M.; Koomen, M. J.; Brueckner, G. E.; Cook, J. W.; Dere, K. P.; Howard, R. A.; Michels, D. J.; Moses, J. D.; Morrill, J. S.; Moulton, N. E.; Paswaters, S. E.; Socker, D. G.; St. Cyr, O. C. St.; Wang, D.; Lamy, P. L.; Llebaria, A.; Bout, M. V.; Schwenn, R.; Podlipnik, B.; Bedford, D. K.; Biesecker, D. A.; Eyles, C. J.; Plunkett, S.; Simnett, G. M. Bibcode: 1996AAS...188.3716A Altcode: 1996BAAS...28..880A The C2 and C3 telescopes on the Large Angle Spectrometric Coronograph (LASCO) have recorded images of a Streamer Blow-out which occured on 03Feb96. We will present a series of images produces by combining data from the 2 coronographs. These images show a rapid evolution of the coronal streamer belt over projected distances of 2 to 20 solar radii. The streamer belt shows a dramatic brightening, which is seen to propagate outward. A bubble-like structure is seen to move away from the Sun and expand. At the end of this event, the equatorial corona is significantly less bright than prior to the event. Title: LASCO Observations of the Solar Corona to 32 Rsun Authors: Cook, J. W.; Koomen, M. J.; Korendyke, C. M.; Brueckner, G. E.; Dere, K. P.; Howard, R. A.; Michels, D. J.; Morrill, J. S.; Moses, J. D.; Socker, D. G.; Paswaters, S. E.; Wang, D.; Moulton, N. E.; Cyr, O. C. St.; Andrews, M. D.; Schwenn, R.; Podlipnik, B.; Lamy, P. L.; Llebaria, A.; Bout, M. V.; Simnett, G. M.; Bedford, D. K.; Eyles, C. J.; Plunkett, S.; Biesecker, D. A. Bibcode: 1996AAS...188.3717C Altcode: 1996BAAS...28..880C The Large Angle Spectrometric Coronagraph (LASCO) was launched on board the SOHO satellite on 2 December 1995. The C3 externally-occulted coronagraph of LASCO observes the solar corona over a field from 3.7-32 R_ ⊙, using a 1024x1024 CCD detector with a pixel size corresponding to 56 arc sec. Observations can be made using color filters ranging from the blue (420-520 nm) to the near-IR (860-1050 nm), and through polarizing filters. We report on early observations of the solar corona out to 32 Rsun. Title: Preliminary Photometric Calibration of LASCO C3 Coronagraph Images using Pre-Flight Laboratory Images of Standard Sources and In-Flight Images of Standard Stars Authors: Korendyke, C. M.; Koomen, M. J.; Andrews, M. D.; Brueckner, G. E.; Cook, J. W.; Dere, K. P.; Howard, R. A.; Michels, D. J.; Moses, J. D.; Morrill, J. S.; Moulton, N. E.; Paswaters, S. E.; Socker, D. G.; St. Cyr, O. C.; Wang, D.; Lamy, P. L.; Llebaria, A.; Bout, M. V.; Schwenn, R.; Podlipnik, B.; Bedford, D. K.; Biesecker, D. A.; Eyles, C. J.; Plunkett, S.; Simnett, G. M. Bibcode: 1996AAS...188.3621K Altcode: 1996BAAS...28..876K The C3 coronagraph is a wide field (+/-8.0 degrees), externally occulted, white light coronagraph. The instrument is one of three coronagraphs comprising the Large Angle Spectrometric COronagraph (LASCO) experiment mounted on the Solar Heliospheric Observatory satellite. The satellite was launched on Dec. 2, 1996; C3 observations began in early Jan. 1997. The coronagraph optical train includes a set of five broadband color filters mounted in a wheel. Prior to flight, an image was obtained through each color filter of a well characterized, rear-illuminated, opal glass diffusing screen. The C3 in-flight images, in addition to the coronal structures, also contain several hundred bright stars. We present a comparison of the photometric calibration derived from standard stars with the laboratory measurements. The resulting calibration is then used to examine color variations in the white light corona over the field of view. The LASCO experiment was developed by a scientific consortium of members from NRL (USA), MPAe (Germany), LAS (France) and U. Birmingham (United Kingdom). Title: Intercalibration and Co-Registration of the LASCO, UVCS and SUMER instruments on SOHO Authors: Michels, J.; Kohl, J. L.; Noci, G.; Antonucci, E.; Tondello, G.; Huber, M. C. E.; Curdt, W.; Hollandt, J.; Lemaire, P.; Schuhle, U.; Wilhelm, K.; Korendyke, C.; Moran, T.; Raymond, J. C.; Romoli, M.; Benna, C.; Ciaravella, A.; Fineschi, S.; Gardner, L. D.; Giordano, S.; Naletto, G.; Nicolosi, P.; Siegmund, O. H. W.; Spadaro, D.; Smith, P. L.; Strachan, L. Bibcode: 1996AAS...188.3706M Altcode: 1996BAAS...28..878M Joint observations of equatorial streamers by three SOHO instruments have been used for radiometric intercalibration, co-registration and other spectroscopic comparisons. The results are used to track the stability of the radiometric calibrations of the Ultraviolet Coronagraph Spectrometer (UVCS) and the Solar Ultraviolet Measurements of Emitted Radiation (SUMER) experiment at overlapping wavelenghs. Observations of equatorial streamers at heliocentric heights from 1.25 to 1.5 R_⊙ are used for the intercalibrations. The results are compared to pre-launch laboratory calibrations and to observations of stars. The first stellar observation was for 38 AQI. These UV observations are compared to coronal green line (Fe XIV) observations obtained with the Large Angle Spectrometric Coronagraph (LASCO) C1 coronagraph obtained in the same time frame. Intercomparisons of spectral line profiles among LASCO, SUMER, and UVCS are also planned. The LASCO research is supported by NASA Grant NDPR S92835D; the UVCS research is supported by NASA Contract NAS5-31250 to the Smithsonian Astrophysical Observatory, by the Italian Space Agency and by Switzerland, and SUMER is financially supported by BMFT/DARA, CNES, NASA and PRODEX (Swiss Contribution). Title: Observations of the comet Hyakutake by the LASCO coronagraph on the SOHO satellite. Authors: Andrews, M. D.; Paswaters, S. E.; Brueckner, G. E.; Korendyke, C. M.; Dere, K. P.; Howard, R. A.; Michels, D. J.; Moses, J. D.; Morril, J. S.; Moulton, N. E.; Socker, D. G.; St. Cyr, O. C.; Wang, D.; Lamy, P. L.; Llebaria, A.; Bout, M. V.; Schwenn, R.; Podlipnik, B.; Bedford, D. K.; Biesecker, D. A.; Eyles, C. J.; Plunket, S.; Simnet, G. M. Bibcode: 1996BAAS...28.1195A Altcode: No abstract at ADS Title: The Large Angle Spectroscopic Coronagraph (LASCO) Authors: Brueckner, G. E.; Howard, R. A.; Koomen, M. J.; Korendyke, C. M.; Michels, D. J.; Moses, J. D.; Socker, D. G.; Dere, K. P.; Lamy, P. L.; Llebaria, A.; Bout, M. V.; Schwenn, R.; Simnett, G. M.; Bedford, D. K.; Eyles, C. J. Bibcode: 1995SoPh..162..357B Altcode: The Large Angle Spectroscopic Coronagraph (LASCO) is a three coronagraph package which has been jointly developed for the Solar and Heliospheric Observatory (SOHO) mission by the Naval Research Laboratory (USA), the Laboratoire d'Astronomie Spatiale (France), the Max-Planck-Institut für Aeronomie (Germany), and the University of Birmingham (UK). LASCO comprises three coronagraphs, C1, C2, and C3, that together image the solar corona from 1.1 to 30 R (C1: 1.1 - 3 R, C2: 1.5 - 6 R, and C3: 3.7 - 30 R). The C1 coronagraph is a newly developed mirror version of the classic internally-occulted Lyot coronagraph, while the C2 and C3 coronagraphs are externally occulted instruments. High-resolution imaging spectroscopy of the corona from 1.1 to 3 R can be performed with the Fabry-Perot interferometer in C1. High-volume memories and a high-speed microprocessor enable extensive on-board image processing. Image compression by a factor of about 10 will result in the transmission of 10 full images per hour. Title: Ultraviolet Observations of the Structure and Dynamics of an Active Region at the Limb Authors: Korendyke, C. M.; Dere, K. P.; Socker, D. G.; Brueckner, G. E.; Schmieder, B. Bibcode: 1995ApJ...443..869K Altcode: The structure and dynamics of active region NOAA 7260 at the limb have been studied using ultraviolet spectra and spectroheliograms obtained during the eighth rocket flight of the Naval Research Laboratory's High Resolution Telescope an Spectrograph (HRTS). The instrument configuration included a narrow-bandpass spectroheliograph to observe the Sun in the lines of C IV lambda 550 and a tandem-Wadsworth mount spectrograph to record the profiles of chromospheric transition region and coronal lines in the 1850-2670 A region. The combination of high spatial resolution and high spectral purity C IV slit jaw images with ultraviolet emission-line spectra corresponding allows examination of a variety of active region phenomena. A time series of spectroheliograms shows large-scale loop systems composed of fine-scale threads with some extending up to 100 Mm above the limb. The proper motion of several supersonic features, including a surge were measured. The accelerated plasmas appear in several different geometries and environments. Spectrograph exposures were taken with the slit positioned at a range of altitudes above the limb and provide a direct comparison between coronal, transition region and chromospheric emission line profiles. The spectral profiles of chromospheric and transition region emission lines show line-of-sight velocities up to 70 km/s. These lower temperature, emission-line spectra show small-scale spatial and velocity variations which are correlated with the threadlike structures seen in C IV. Coronal lines of Fe XII show much lower velocities and no fine structure. Title: Spectrometric and spectropolarimetric observation of the solar corona with the LASCO/SOHO Lyot coronagraph Authors: Socker, Dennis G.; Brueckner, Guenther E.; Korendyke, Clarence M.; Schwenn, Reinhard Bibcode: 1994SPIE.2283...53S Altcode: A spectrometric and spectropolarimetric visible light Lyot coronagraph are scheduled for launch in 1995 on the ESA/NASA Solar Heliospheric Observatory (SOHO) mission. The Lyot coronagraph is one of three coronagraph optical trains contained in the NASA sponsored large angle spectrometric coronagraph (LASCO) which will be used to study the emission line, electron, and dust components of the solar corona within a 30 solar diameter field of view. This talk focuses on the spectrometric and polarimetric capabilities of the Lyot optical train which covers the inner solar corona from 1.1 - 3.0 solar radii. Title: Combined HRTS-8 Sounding Rocket Observations and YOHKOH Soft X-ray Observations of NOAA Active Region 7260 at the Solar Limb Authors: Korendyke, C. M.; Dere, K. P.; Brueckner, G. E.; Waljeski, K.; Lemen, J. R. Bibcode: 1994kofu.symp..293K Altcode: On 24 August 1992, the Naval Research Laboratory (NRL) High Resolution Telescope and Spectrograph (HRTS) was launched aboard a Black Brant sounding rocket from White Sands, New Mexico. During the flight, the instrument recorded a unique set of near ultraviolet slit spectra and 1550 A spectroheliograms of an active region at the solar limb. An extensive set of observations of this region were obtained with the Yohkoh Soft X-ray Telescope (SXT) near the time of the flight. The C IV spectroheliograms obtained during this flight are some of the highest resolution images of the solar transition region ever obtained. The spectra and spectroheliograms dramatically demonstrate the fundamental difference between coronal and chromospheric/transition-region plasmas at 700 km spatial scales. The cooler plasmas exhibit a great deal of dynamic, fine scale structure with significant flows or proper motion particularly in the transition zone loops. The coronal emission lines in the spectra! are relatively uniform and quiescent. The Yohkoh data during the period before and after the flight show a set of diffuse high temperature coronal loops with only minimal correspondence to the structures visible in the C IV spectroheliograms. Title: Optical design of a near-ultraviolet coronagraph for a sounding rocket platform Authors: Korendyke, Clarence M.; Prinz, Dianne K.; Socker, Dennis G. Bibcode: 1994OptEn..33..479K Altcode: The near-UV (190 to 270 nm) coronal emission lines present a unique opportunity to observe heliospheric plasmas between one and two solar radii. The near-UV coronagraph was specifically designed to obtain observations in these lines from a sounding rocket platform. The design demonstrates that high-resolution, two-dimensional coronal observations in the near-UV are readily achievable within the practical constraints of a sounding rocket. The near- UV coronagraph consists of a reflective, coronagraph telescope followed by an imaging channeled spectrograph. The telescope includes a Lyot stop and an occulter to minimize instrumentally scattered disk radiation. The choice of a mirror objective gives rise to a compact, achromatic telescope with excellent off-axis rejection and good imaging properties. The focal plane package combines a Fabry-Perot interferometer with a tandem Wadsworth spectrograph to produce a channeled spectrum consisting of a series of two-dimensional (25 X 500 arcsec), narrow-bandpass (approximately 0.1 angstroms) images at the instrument focal plane. The instrument will produce a number of high-spatial-resolution (< 1 arcsec) coronal images in a single flight. Title: Status of the LASCO Instrument Development Program Authors: Moses, D.; Brueckner, G. E.; Howard, R. A.; Koomen, M. J.; Korendyke, C. M.; Michels, D. J.; Socker, D. G.; Lamy, P.; Schwenn, R.; Simnett, G. M. Bibcode: 1993BAAS...25.1192M Altcode: No abstract at ADS Title: A Description of the HRTS-8 Instrument Configuration Authors: Korendyke, C. M.; Dere, K. P.; Brueckner, G. E.; Socker, D. G. Bibcode: 1993BAAS...25.1182K Altcode: No abstract at ADS Title: HRTS Untraviolet Observations of the Chromosphere Transition Region and Corona of a Solar Active Region Authors: Dere, K. P.; Korendyke, C. M.; Brueckner, G. E. Bibcode: 1993BAAS...25.1182D Altcode: No abstract at ADS Title: Description and Performance of the Recently Completed Naval Research Laboratory Solar Instrument Test Facility Authors: Korendyke, C. M.; Brueckner, G. E.; Koomen, M. J.; Michels, D. J. Bibcode: 1993BAAS...25.1191K Altcode: No abstract at ADS Title: The Large Angle Spectroscopic Coronagraph (LASCO): visible light coronal imaging and spectroscopy. Authors: Brueckner, G. E.; Howard, R. A.; Koomen, M. J.; Korendyke, C.; Michels, D. J.; Socker, D. G.; Lamy, P.; Llebaria, A.; Maucherat, J.; Schwenn, R.; Simnett, G. M.; Bedford, D. K.; Eyles, C. J. Bibcode: 1992ESASP.348...27B Altcode: 1992cscl.work...27B The Large Angle Spectroscopic Coronagraph (LASCO) is a triple coronagraph being jointly developed for the SOlar and Heliospheric Observatory (SOHO) mission by the Naval Research Laboratory (USA), the Laboratoire d'Astronomie Spatiale (France), the Max Planck Institut für Aeronomie (Germany), and the University of Birmingham (UK). LASCO comprises three nested coronagraphs (C1, C2, and C3) that image the solar corona from 1.1 Rsun to 30 Rsun. Title: LASCO - Large Angle Spectrometric Coronagraph for SOHO Authors: Howard, R. A.; Brueckner, G. E.; Dere, K. P.; Korendyke, C. M.; Koomen, M. J.; Michels, D. J.; Moses, D.; Socker, D. G.; Schwenn, R.; Inhester, B.; Lamy, P.; Maucherat, A.; Simnett, G. M.; Eyles, C. Bibcode: 1992AAS...180.3307H Altcode: 1992BAAS...24..781H No abstract at ADS Title: The Optical Design of the Spectrocoronagraph: an Ultraviolet Coronagraph Payload for a Sounding Rocket Platform Authors: Korendyke, Clarence Marinus Bibcode: 1992PhDT........14K Altcode: The spectrocoronagraph was specifically designed to observe the solar corona utilizing the relatively unexplored near-UV emission lines present above the solar limb. These lines were first observed by the Naval Research Laboratory Skylab spectrograph and are relatively bright with respect to the solar disk. They contain a number of useful plasma temperature and density diagnostics. The instrument allows a large number of high spatial resolution (<1 arc-second), narrow bandwidth (~0.1A), two dimensional coronal images in these emission lines to be obtained during a single sounding rocket flight. These observations will yield valuable information on the dominant physical processes present in the inner corona. The spectrocoronagraph consists of a low stray light telescope followed by an imaging spectrograph. The telescope and spectrograph designs incorporate new features to enhance their performance. The coronagraph telescope design includes a Lyot stop and an occulter to reduce instrument stray light levels. The nontraditional choice of a mirror objective allows a compact design with superb solar rejection, no chromatic aberration and excellent imaging properties. The focal plane package utilizes a Fabry-Perot (FP) interferometer in series with a grating spectrograph to produce a channelled spectrum consisting of a series of two dimensional, narrow bandwidth images at the instrument focal plane. All significant optical performance issues have been examined and resolved. The optical performance of near-UV FP interferometer coatings was investigated and found to be sufficient for this application. Measurements of visible and near-UV scattered light from two superpolished mirrors were obtained. The visible measurements showed that the near specular scattered light from these mirrors was equivalent to or better than scattered light from coronagraph quality lenses and mirrors described in the literature. The scattered disk radiation originating at the mirror objective was predicted from the near-UV measurements and compared favorably with coronal intensites at the focal plane. Title: The Prime Energy Release of a Solar Flare Authors: Brueckner, G. E.; Moses, D.; Cook, J. W.; Dere, K. P.; Korendyke, C. M.; Socker, D. G.; Bartoe, J. -D. F. Bibcode: 1991BAAS...23.1026B Altcode: No abstract at ADS Title: Flaring Active Region Structures in the Corona, Transition Region, and Lower Atmosphere Observed in the SAROC Authors: Moses, D.; Brueckner, G. E.; Cook, J. W.; Dere, K. P.; Korendyke, C. M.; Socker, D. G.; Bartoe, J. -D. F. Bibcode: 1991BAAS...23.1026M Altcode: No abstract at ADS Title: The OSL/HRTS VUV CCD Development Program Authors: Socker, D. G.; Marchywka, M.; Korendyke, C. Bibcode: 1991BAAS...23.1037S Altcode: No abstract at ADS Title: The HRTS/OSL Vacuum Ultraviolet CCD Development Program Authors: Socker, D. G.; Dere, K. P.; Korendyke, C. M. Bibcode: 1990BAAS...22..889S Altcode: No abstract at ADS Title: Imaging channeled spectrograph: a high resolution spectrometer providing multiple simultaneous 2-D monochromatic images over a large spectral range Authors: Korendyke, Clarence M. Bibcode: 1988ApOpt..27.4187K Altcode: An imaging channeled spectrograph (ICS) consists of a Fabry-Perot bandpass filter followed by a wide-slit imaging grating spectrograph. This unique configuration combines the two-dimensional monochromatic imaging of a Fabry-Perot system with the high resolution and comprehensive wavelength coverage of a grating spectrograph. The ICS produces a series of simultaneous, high-resolution, nonoverlapping, two-dimensional monochromatic images uniformly distributed over a large spectral range. This paper describes the ICS optical properties in general and calculates the optical performance of an ICS designed for the proposed NRL spectrocoronagraph. Title: Optical Properties of a near-UV Solar Imaging Channelled Spectrograph Authors: Korendyke, C. M.; Socker, D. G. Bibcode: 1988BAAS...20..990K Altcode: No abstract at ADS Title: Stray Light Measurements of Reflecting Coronagraph Mirrors at lambda = 6328 Å Authors: Socker, D. G.; Korendyke, C. M. Bibcode: 1988BAAS...20..990S Altcode: No abstract at ADS Title: Imaging and spectral performance of Fabry-Perot interferometers at 2288 Å. Authors: Socker, D. G.; Korendyke, C. M. Bibcode: 1986BAAS...18..851S Altcode: No abstract at ADS