Calibration experiments of the CRL/NASDA X/L-band airborne synthetic aperture radar

The Communications Research Laboratory (CRL) and the National Space Development Agency of Japan (NASDA) have jointly developed a new airborne synthetic aperture radar system operated at X-band and L-band. Both the X- and L-band radars have polarimetric capability and the X-band one has interferometric capability. The radar system is on board a Gulfstream-2 aircraft whose navigation altitude is 20000 to 40000 feet. Following system performance test flights in August 1996, there is a series of calibration ongoing flights. For calibration of the X-band SAR, the authors have developed an active radar calibrator (ARC) at the CRL. The ARC is designed to return H and V radar signals simultaneously with two transmission antennas for polarimetric calibration. It will be employed, along with several corner reflectors, in calibration experiments planned in May and October 1997 at the Tottori dune area in Japan. In this paper, the authors present a plan of the experiments and a procedure to calibrate the SAR system, focusing on the X-band SAR.