Abstract:

For squint terrain observation by progressive scans (TOPS) synthetic aperture radar (SAR) mode, this paper proposes a new full-aperture imaging algorithm. Firstly, the two dimensional (2-D) spectrum without aliasing is obtained by the azimuth pre-processing after range walk correction. Then the modified chirp scaling algorithm is used to complete range compression and range cell migration correction (RCMC). After that, by using a frequency nonlinear chirp scaling (FNCS) method in the range Doppler domain, the variation of the FM rates is corrected, and the signal is focused in the Doppler domain by SPECAN technique. Finally, geometric distortion correction is carried out. Both simulation and real data processing results demonstrate the effectiveness of the proposed method.