fast imaging in ground-based circular strip-map synthetic aperture radar

at first, ground-based circular strip-map synthetic aperture radar (gb-csmsar) and its capabilities is introduced and the received signal model, 2-d frequency spectrum and the azimuth and range resolutions are derived and compared with the linear motion strip-map sar resolutions. because of the stability of the path and speed of antenna in gb-csmsar a frequency domain imaging algorithm is suggested that includes a 2-d fft of raw data, multiplication in reference data and a phase correction step in the range-doppler domain. simulations verify the accuracy of the suggested algorithm in image formation of targets in polar coordinates. it is shown that the speed of the algorithm can be increased and the needed memory can be decreased by omitting the phase correction step for targets with ranges near to reference range. finally the location of targets that don’t need phase error correction is extracted as “fast imaging region” according to the geometry and parameters of the system.