Journal of Radars (雷达学报) 2013/2:4 PP.492-498
The measurement inaccuracies of Inertial Measurement Unit/Global Positioning System (IMU/GPS) as well as the positioning error of the target may contribute to the residual uncompensated motion errors in the MOtion COmpensation (MOCO) approach. Aiming at the effects of target positioning error on MOCO for airborne interferometric SAR, the paper deduces a mathematical model of the residual motion error caused by the target positioning error under the condition of squint. Also, the effects of the system sampling delay, Doppler center frequency, and reference DEM errors on the residual motion error that result in target positioning error based on the model are analyzed. Then, the paper discusses the effects of the reference DEM error on the interferometric SAR image quality, the interferometric phase, and the coherent coefficient. The research provides theoretical basis for the MOCO precision in signal processing of the airborne high precision and airborne repeat-pass interferometric SARs.