SIR-B (Shuttle Imaging Radar) images
Abstract
Space Shuttle Mission 41G was launched from Kennedy Space Center on 5 October 1984. Aboard the instrument pallet was the 1.28 GHz (L-band) Shuttle Imaging Radar (SIR-B) intended to obtain SAR images for geology, agriculture, forestry, hydrology, and ocean sciences. Data were intended to be transmitted to earth via a Ku band communication link with the Tracking and Data Relay Satellite (TDRS). Unfortunately, the shuttle's trainable Ku communication antenna failed to lock onto the TDRS, making high rate data transmission impossible. A real-time-revised observation program, of much smaller scale than the original plan, was substituted making use of an onboard tape recorder. The flight crew recorded radar data on the recorder and then reoriented the shuttle itself, with the Ku antenna fixed, to point to TDRS and transmit the data. The revised plan eliminated about 80 percent of the planned data swaths and shortened the remainder. A number of errors crept into the SIR-B experiments as a result of the sudden and complete reprogramming as well as a problem in latching the radar antenna. Finally, an electrical problem in the radar caused an 8-10 dB reduction in signal-to-noise ratio.
- Publication:
-
NASA STI/Recon Technical Report N
- Pub Date:
- May 1985
- Bibcode:
- 1985STIN...8625655.
- Keywords:
-
- Data Transmission;
- Instrument Errors;
- Radar Imagery;
- Shuttle Imaging Radar;
- Signal To Noise Ratios;
- Superhigh Frequencies;
- Computer Programming;
- Data Links;
- Directional Antennas;
- Radar Antennas;
- Tape Recorders;
- Tdr Satellites;
- Communications and Radar