Channel Calibration Method for ISAR Imaging System

When the inverse synthetic aperture radar (ISAR) system images the target, the radar emits a wide band linear frequency modulation (LFM) signal. The received echo is modulated by the radar transmitting channel and receiving channel, which is no longer an ideal LFM signal. Then the echo is mismatched with the ideal matched filter, which results in the range profile defocusing. In order to improvSe the imaging quality, a channel calibration method for the ISAR imaging system is proposed in this paper. Firstly, the radar illuminates nearby fixed-point target and receives the baseband echo. Secondly, construct the channel calibration coefficient with an ideal matched filter to eliminate the adverse effect on imaging caused by the non-ideal characteristics of transmitting channel and receiving channel. Simulation experiments verified the effectiveness of the proposed method.