Data Handling

Realtime and playback telemetry data will be received at the EOF, while the final flight data will be sent to SAO and the Italian Data Analysis Centers. In either case, the telemetry sorter will separate science data from housekeeping data and convert the UV detector data to image format. At the EOF, quick-look images will be used to verify data quality for planning purposes, to produce the daily summary data files for the ECS, and to carry out some preliminary scientific analyses. The Data Reduction and Analysis Facility (DRAF) at SAO will produce and distribute the definitive data set from the final flight data. Data products to be distributed to investigators and to the SOHO data archive include the following:

1. Spectral Data Files: These are FITS files containing uncalibrated detector count data (counts per pixel), as well as instrument configuration and exposure timing data. Each observing sequence will produce one spectral data file per detector.

2. Visible Light Data Files: These are FITS files containing the time series of count rates from the WLC, along with pointing information and information on the polarizer and neutral density filter. Each VL data file will contain the data corresponding to one observing sequence.

3. Calibration Data:
   1. Parameter files for pointing, spatial, wavelength and radiometric calibrations (ascii)
   2. Flat field and dark count data (FITS)
   3. SOHO orbit and attitude data

4. Image Data Files, including synoptic maps: These are FITS files such as the Ly- maps of the corona to be provided as part of the Summary Data.

5. Auxiliary Data Files: These include the disk irradiance history (as determined from periodic pointings at the solar disk), measurements of the instrument profile, stray light data, and pulse height distribution data.

6. Data Catalogs: These will include a database to permit users to select observations based on pointing, observation date, type of feature observed, or other criteria. They also include the Mission Log File, which records the observing sequences and other commands sent to the instrument, as well as an evaluation of the data quality.

7. Data Analysis Software: This IDL software is used for display and analysis of the science data. It can read and write FITS format Spectral and Visible Light Data Files, display the 2D spectral data, carry out the calibration procedures to correct for instrument response, perform wavelength and pointing calibrations, and transform the science data into physical units (photons ), and perform some basic functions for measuring line profiles and intensities. Software will also be available to transform a set of spectra covering different radial and roll positions into images, including the daily images to be provided to the Experimenters Control System (ECS) as part of the Summary Data. The Data Analysis Software will be used at various sites including the EOF and Experiment Analysis Facility (EAF) at Goddard Space Flight Center, the DRAF at SAO, the Italian Centers, the Multi-Experiment Data and Operations Center (MEDOC), and other co-investigator institutions. It will require the calibration files listed above as well as the final orbit/attitude files supplied by NASA to determine the pointing from the instrumental parameters and to wavelength and flux calibrate the spectral data files.

Acknowledgements

The UVCS instrument is the result of the work of many individuals and organizations. Although we will not attempt to list every name, we wish to thank and acknowledge the contributions of each person who contributed to the instrument development. They include managers, engineers and scientists at Alenia, Ball Electronics and Cryogenics Division, Composite Optics Inc., ESTEC, Goddard Space Flight Center, Hyperfine Corporation, Observatoire de Marseille, Officine Galileo, Oerlikon-Contraves, Optical Filter Corporation, Smithsonian Astrophysical Observatory, United Technologies Inc., Atomic Ltd., and The University of California at Berkeley. Especially, we wish to thank K. Sizemore, D. Machi, P. Rabino, J. Shannon, B. Sherman, R. Blum, and P. Sozanski for their skillful program management. We also wish to thank W. Koldewyn, R. Novaria, J. Burkepile, R. Reinker, S. Varlese and W. Frank for managing the instrument development at the Ball Electronics and Cryrogenics Division. Special recognition for extra effort and dedication go to N. Adler, B. Bach, W. Blanco, P. Carosso, R. Carter, J. Coberly, M. Coyle, M. Dami, N. Galluccio, P. Giordano, D. Leviton, J. Marriott, S. Reynolds, M. Tardy, and R. Voorhees. We particularly thank C. Berner, D. Bock, D. Dale, V. Domingo, F. Felici, K. Kirby, A Poland, and I. Shapiro for their extra efforts in accommodating the specific requirements of the UVCS program. The UVCS instrument is the result of the knowledge, skill and efforts of many talented persons including the following who deserve special mention: J. Austin, M. Bartuli, K. Belmont, D. Boyd, S. Burcar, N. Carosso, J. Chappell, E. Ciancetta, A. Cisbani, L. Condello, A. Copty, R. Czichy, R. Faust, G. Ferrari, S. Fike, R. Gemma, J. Girard, D. Hassler, D. Herhager, C. Highman, D. Hill, D. Hillis, M. Honsa, M. Kilpatrick, R. Koehler, D. Langjahr, E. Lear, R. Mathews, A. Melikian, G. Mondello, T. Moran, M. Ostaszewski, P. Pellegrino, L. Poletto, H. Radford, D. Reisenfeld, F. Rivera, D. Rose, L. Suedmeier, M. Vitali, S. Wenners, S. Woolaway, and K. Yoshino. The UVCS program is indebted to the XDL detector team at the University of California at Berkeley and Lockheed including: M. Gummin, T. Sasseen, B. Welsh, G. Gaines, J. Hull, P. Jelinski, R. Raffanti, J. Stock, J. Tom, T. Magoncelli and E. Hertzberg. Thanks also to P. Martens, B. Fleck, and L.D.Sanchez for their extra efforts toward UVCS. We thank C. Hickey of the Harvard College Observatory, and Peter Dandridge Sr. and Peter Dandridge Jr. of Atomic Limited for their work in preparing for the UVCS end-to-end test. We thank W. Parkinson for stimulating discussions and wise council. We also thank the following members of the UVCS Science Team: J. Armstrong, P. Bochsler, A. Bürgi, W.A. Coles, A. Galvin, G.A. Gary, M. Hagyard, L. Hartmann, J. Hollweg, F. Ipavich, E. Jannitti, M. Karovska, G. Lemaitre, R. Kopp, M. Machado, M. Malvezzi, S. Massaglia, M. Messerotti, R. Moore, F. Reale, B. Rickett, R. Rosner, S. Suess, G. Timothy, G. Tozzi, and H. Weiser. We thank those at NASA Headquarters and Agenzia Spaziale Italiana for their extra time and talents which were so vitally important to this program. A very special thank you to L. Gagliardi for his dedication to the program and his high standards of excellence. Finally, we wish to thank B. Bernard for her many contributions to the UVCS program including the coordination and preparation of this manuscript. The UVCS program is supported by the National Aeronautics and Space Administration under contract NAS5-31250 to the Smithsonian Astrophysical Observatory, by Agenzia Spaziale Italiana and by Swiss Funding Agencies.