Initial Results of Geometric Calibration of Interferometric Cartwheel SAR HT-1

The Hongtu-1 (HT-1) is the world’s first commercial interferometric synthetic aperture radar (InSAR) satellite cartwheel constellation performing an Earth observation mission. HT-1 comprises four X-band SAR satellites, one designated as the primary satellite and the remaining three as auxiliary satellites. For operationally generated Level-1 SAR products, a precise geometric calibration has been carried out since the Commissioning Phases. This paper reports four satellites’ initial geometric calibration and absolute location error results with different beams and modes based on the improved RD model.