Airborne SAR processing using the chirp scaling and a time domain subaperture algorithm

Abstract

The paper proposes a new approach for high resolution airborne SAR data processing, which uses a modified chirp scaling algorithm in order to incorporate the correction of strong motion errors as well as large the variations of the Doppler centroid in range and azimuth. Additionally, data acquired with squint angle greater than 40/spl deg/ can be processed with less than 3.5% degradation of geometric resolution. A time domain subaperture approach can be used in range compression for accommodating the variation of the frequency modulation of the chirp signal and also the variation of the secondary range migration, which are caused by the modified chirp scaling algorithm. Further, the time domain subaperture approach can be used in azimuth for incorporating the Doppler centroid variations in azimuth. >