Processing of Spaceborne Imaging Radar-C (SIR-C) Data at Full Resolution
Abstract
The Spaceborne Imaging Radar-C (SIR-C) was the first spaceborne multi-frequency, polarimetric synthetic aperture radar (SAR) system. Built and operated by NASA's Jet Propulsion Laboratory (JPL), SIR-C was also a precursor to other spaceborne SAR systems (e.g., SRTM and NISAR). SIR-C flew twice aboard the space shuttle Endeavor in 1994, once in April and again in September/October. Throughout both shuttle mission, SIR-C recorded a total of 143 hours (93 terabits) of SAR data. However, the SIR-C dataset has particular scientific value because it was acquired simultaneously in dual microwave frequencies (L-band and C-band). With respect to earth monitoring in L-band, SIR-C provides greater time continuity between the Seasat (1978) and ALOS (2006-2011) missions.
The Alaska Satellite Facility (ASF), as a NASA Distributed Active Archive Center (DAAC), strives to make remote-sensing data accessible to everyone, including the scientific community. In accordance with this goal, ASF has built a SIR-C processor based on JPL specifications, and it is currently processing all of the SIR-C data at full resolution, which is more appropriate for scientific analysis. ASF plans on making SIR-C SLC, MLC, and high resolution geocoded image products available through its existing data archiving and distribution system. SIR-C data were acquired in a total number of 14 modes, differing by the number of polarization, pulse repetition frequencies (PRFs), bandwidths, and range resolution. The processing priority is based on the number of data sets acquired in the various modes: mode 11 (29.1 %), mode 16 (26.3 %), mode 13 (15.0 %) and mode 20 (10.5 %). All quad-pol data (mode 16) are provided as covariance matrices to allow straight-forward polarimetric processing. The processing flow consists of four steps. In the first step, the original data in demultiplexed header/signal data (DMX) format were decoded and cleaned to reduce the bit error rate. During the pre-processing step, the data are rearranged to enable the use of the same SAR processor for all modes. The SAR processor follows the range-Doppler processing principle to focus SIR-C raw data into SLC or MLC (for quad-pol data) data. In the final post-processing step, an antenna pattern correction is performed and calibration parameters are applied.- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2018
- Bibcode:
- 2018AGUFM.G41B0689A
- Keywords:
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- 1240 Satellite geodesy: results;
- GEODESY AND GRAVITYDE: 1241 Satellite geodesy: technical issues;
- GEODESY AND GRAVITYDE: 1908 Cyberinfrastructure;
- INFORMATICSDE: 1932 High-performance computing;
- INFORMATICS