On-orbit calibration of the scatterometer on HY-2 using Active Radar Calibration

The Active Radar Calibration(ARC) is an important on-orbit calibration device of scatterometer., which can both receive and retransmit the signal of the scatterometer. The ARC purpose is to prove the precision of Radar Cross Section(RCS) and to measure very accurately the radar pulse timing., frequency and the antenna pattern in order to monitor independently the scatterometer on HY-2 over the mission. We use the output data of the ARC to estimate the key parameters and on-orbit antenna pattern of scatterometer. Result is presented in this paper which show the ability to measure scatterometer pulse timing to microsecond detail and the precision of the antenna beamwidth to better than 0.1degrees.