NSSDCA ID: ASIR-00058
Availability: Archived at NSSDC, accessible from elsewhere
The Infrared Astronomical Satellite (IRAS) Zodiacal Observational History File (ZOHF) was created as an aid to modeling and extracting the zodiacal emission contribution to the IRAS extended emission data products. Two versions of the ZOHF - low and medium resolution - represent survey data from the IRAS focal plane array as time series observations of the celestial sphere binned to the same cross-scan (0.5 degrees) but different in-scan resolutions (0.5 and 0.033 degrees, respectively). Subdivision of the original survey into semi-daily Satellite Operation Programs (SOPs) and individual continous survey scan observations (OBS) is retained. The ZOHF is provided on a set of four CD-WOs. Three CD-WOs hold both versions of the ZOHF in ASCII form. Volume 1 contains the Low Resolution ZOHF (5749 tables) and SOPs 29 - 179 from the Medium Resolution ZOHF (1448 tables); the remainder of the Medium Resolution ZOHF is given on volumes 2 and 3, SOPs 180 - 399 (2225 tables) on volume 2 and SOPs 400 - 600 (2076 tables) on volume 3. A fourth CD-WO contains both versions of the ZOHF in binary form in two files and files that provides record locations and lengths to enable decoding of the binary data. Files giving the system spectral response functions (filter files) for the four IRAS photometric bands and an observation geometry (scan history) file are also provided to support analysis of these and other IRAS data products. IRAS data products were produced by the Infrared Processing and Analysis Center (IPAC), which is operated by the California Institute of Technology, Jet Propulsion Laboratory under contract to NASA. The IRAS ZOHF and supporting calibration and index files were organized on CDs by the Dust Subnode of the Small Bodies Discipline Node of the NASA Planetary Data System for distribution to the general community. The Low Resolution ZOHF has PDS ID: IRAS-D-FPA-3-RDR-ZOHF-LOW-RES-V1.0 and the Medium Resolution ZOHF has PDS ID: IRAS-D-FPA-3-RDR-ZOHF-MEDIUM-RES-V1.0. IRAS conducted three surveys of the sky in four broad passbands centered at 12, 25, 60, and 100 microns. The principal instrument was a focal plane array of 62 detectors, divided into eight parallel modules, two for each wavelength band. Each module contained either seven or eight detectors. As the satellite orbited the Earth the array swept out a path 0.5 degrees in width. The parallel modules allowed for discrimination between astrophysical sources (stars, asteroids) and spurious signals due to cosmic ray strikes and Earth orbiting debris.
Questions and comments about this data collection can be directed to: Dr. David R. Williams
Name | Role | Original Affiliation | |
---|---|---|---|
Dr. Mark V. Sykes | General Contact | University of Arizona | msykes@as.arizona.edu |