The progress of the airborne SAR calibration techniques in China

Two airborne SAR systems have been developed by IECAS in China, one operates at X-band, another at L-band. In order to develop the potential quantitative uses, they have calibrated these two SAR systems. This paper describes the progress of the airborne SAR calibration techniques in China. In internal calibration, the transmitted signal power was monitored and the receiver gain was measured. In external calibration, different kinds of trihedral corner reflectors and active calibrator (transponder) have been developed. Calibration experiments have been carried out in recent years. The experiments show that the radiometric calibration accuracy of these two SAR systems is better than 2 dB. The authors also describe their future research work, which focus on spaceborne SAR calibration and polarimetric SAR calibration