Nonuniform resampling for staggered SAR

Staggered SAR is an innovative 2-D imaging system utilizing the digital beam-forming (DBF) technique and the continuous variation of pulse repetition frequency (PRF). However, due to the PRF variation, the echo data in the azimuth is non-uniformly sampled. To achieve good imaging quality, it is indispensable to interpolate the data of the staggered SAR to be uniform before further imaging processing. In order to realize efficient interpolation for different PRF variation schemes, we propose a non-uniform fast Fourier transform (NUFFT)-based interpolation method to resample the non-uniform data of the staggered SAR in this paper. The complexity of the proposed interpolation method is in the order of O(MlogM), where M is the number of azimuth sampling. Simulation is performed based on the echo data of point target from the staggered SAR.