The Space Radar Laboratory - 1 (SRL-1) was launched onboard the Space Shuttle "Endeavor" (STS-59) on April 9, 1994. The SRL-1 consists of two elements: a suite of radar instruments called the ... Spaceborne Imaging Radar-C/X-Band Synthetic Aperture Radar (SIR-C/X-SAR) jointly developed by NASA and DARA of Germany and ASI of Italy, and the Measurement of Air Pollution from Satellite (MAPS) instrument to measure atmospheric air pollution. SRL-1 is the first in a series of flights of this payload designed to (1) acquire radar imagery of the Earth's surface for studies in geology, geography, hydrology, oceanography, agronomy, and botany; (2) gather data for future space-borne radar systems; and (3) provide measurements of the global distribution of carbon monoxide (CO) in the troposphere. Instruments on board include the Shuttle Imaging Radar-C (SIR-C) with multi-frequency (C- and L-Bands), multi-polarization (HH, VV, HV, VH), and multi-incidence angle (15 to 55 degrees) capabilities thus lending itself to a wide range of earth surface applications; the X-band Synthetic Aperture Radar (X-SAR), an X-band, VV-polarized imaging radar system, built by Dornier (Germany) and Alenia (Italy) for the German Space Agency (DARA)/German Aerospace Research Establishment (DLR) and the Italian Space Agency (ASI); and, the Mapping Air Pollution from Space (MAPS) instrument for the study of global air pollution. The MAPS instrument, from NASA Langley Research Center (LaRC) is part of NASA's Mission to Planet Earth (MtPE) Program. Four 45-Mbps data channels were recorded on special high data rate tape recorders and real-time data was transmitted to ground stations. About 50 hours each of SIR-C and X-SAR data were recorded during the mission. The combined SIR-C/X-SAR Science Team was made up of 49 members and 3 associates representing 13 countries. SIR-C/X-SAR data collection was focused on several worldwide supersites and correlated with ground and aircraft measurements. Radar data was also calibrated to allow comparisons with other operating spaceborne radars (ERS-1 SAR, JERS-1 SAR).
Both SIR-C and X-SAR will use on-board tape recorders to store data as well as limited real-time transmissions to the ground. Each radar has its own on-board data handling system and each radar can have its data routed through the TDRSS for real-time transmission (Ku-band). SIR-C data are recorded in parallel and X-SAR data is recorded serially. SIR-C and X-SAR data will be preprocessed at the Payload Operations Control Center (POCC) at NASA/JSC before delivery to JPL and operations centers in Germany and Italy. Commands are sent to the SRL-1 from POCC. At mission end, data tapes recorded on-board are sent to the PI sites.
The SIR-C/X-SAR part of the SRL-1 mission is expected to collect over 50 hours of data, both recorded and real-time. Real-time raw data will be pre-processed by the instrument PIs and science teams and stored at the PI sites at JPL, in Germany, and in Italy for analysis. SIR-C data will be processed at JPL using the JPL advanced digital SAR processor, leading to processed SAR images on 8-mm digital tape and on film. Plans include the production of CD-ROMs with 100 m resolution images. X-SAR data will be pre-processed within 3 months. Image products will be made available to X-SAR investigators. Both Germany and Italy will operate separate archives and processing facilities for X-SAR data. SIR-C processed data will eventually be be archived with the EOSDIS DAAC at EROS Data Center. All processed MAPS data is expected to be archived with the EOSDIS DAAC at NASA/Langley. Two additional flights of SRL are planned (August 1994 and 1995).
Some SIR-C and X-SAR images are publically available on the Jet Propulsion Laboratory (JPL) FTP site: jplinfo.jpl.nasa.gov in the directory /sircxsar. The images are also available through the World Wide Web (WWW) at http://www.jpl.nasa.gov/. Both servers also have extensive information about the mission.