L and S Band Airborne SAR Campaign Over USA: Data Processing and Calibration

L and S Band airborne SAR (LS-ASAR) is dual band full polarimetric SAR developed by ISRO as a precursor to NISAR project. It is a test-bed for demonstrating the RF and Digital hardware components developed for S band SAR payload in NISAR. With the simultaneous acquisition of L and S Band full polarimetric SAR data, scientific studies related to target characterization in these bands can be carried out for various themes of NISAR. Initially, operational flights were conducted in 2016-2018 over Indian regions catering to Ecosystem, Disaster and calibration themes. Further, LS-ASAR was flown in two phases over various sites in USA catering to science themes like cryosphere, Solid Earth in addition to themes covered in Indian flights. Acquired data were processed using range Doppler algorithm with software based motion compensation. Algorithm ensures registered data products across L and S bands for all polarizations. Radiometric and phase corrections were established using point targets and distributed targets to generate calibrated data products.