SAR signal reconstruction from multi-channel non-uniform sampling near singular points

Abstract

The technique of multiple apertures in azimuth enables a wide swath synthetic aperture radar (SAR) with a high azimuth resolution. In a traditional multi-channel SAR system, if the pulse repetition frequency (PRF) is not an optimum value it will result in a non-uniform sampling. To overcome this limitation, a reconstruction algorithm has been designed to recover the non-uniform signal. In this letter, we claim that while the system PRF is around some specific values, singular points exist in the reconstruction algorithm and therefore the reconstruction cannot get correct result. To avoid the influence of these singular points, a novel method is presented in this letter which can also improve the system signal-to-noise ratio. Furthermore, simulation results are presented to evaluate the performance of this method. At the end of this letter, the real multi-channel SAR data are processed to demonstrate the effectiveness of the proposed method experimentally.