The Method of Imaging For Air-borne Sliding Spotlight SAR

Aiming at airborne sliding spotlight synthetic aperture radar (SAR) high-resolution imaging, a correction algorithm of system channel error using reference signal and a motion compensation method for airborne sliding spotlight mode is proposed. Integrated with the BAS algorithm, an innovative imaging procedure for airborne sliding spotlight SAR is presented. Firstly, the factor of amplitude correction and phase compensation by means of reference signal for echo data is derived from frequency-domain. Then, the motion compensation is studied based on squint geometry model， the relationship expression between Doppler parameters and platform motion parameters is deduced. After that, the motion error is estimated and compensated using the Doppler parameters estimated exactly from measured echo data. The successful high-resolution sliding spotlight imaging of airborne measured data for a certain space-borne SAR system validation shows the effectiveness of proposed method.