Inter-Comparability of Radiometric Performance between Sentinel-1A and Sentinel-1B

Abstract:
The study shows that Sentinel-1B is more sensitive for low backscatter due to higher TX power and higher RX pattern gain compared to Sentinel-1A. Therefore targets covering a wide backscatter range are compared. While for point targets and medium backscatter areas (e.g. rainforest) no significant radiometric differences are found, the NEBZ within calm water is lower for Sentinel-1B compared to Sentinel-1A by about 1.4 dB. By evaluating transponder recordings, the SAR transmit power is found to be higher for Sentinel-1B compared to Sentinel-1A by about 0.7 dB. These different radiometric performances are present although both SAR systems are well calibrated.