Study on coding scheme for space-pulse-phase-coding-based high-resolution and wide-swath SAR imaging

摘要

There is a conflict between increasing the image swath and improving the azimuth resolution in a conventional single-channel synthetic aperture radar (SAR) system. This paper introduces a method of realizing high-resolution and wide-swath (HRWS) SAR imaging with a multiple-input multiple-output (MIMO) system based on a space-pulse phase coding (SPPC) technique, which makes it possible to discriminate and separate the echoes from multiple ambiguous range regions through coding the phases of the transmitted pulses in each spatial channel. Two coding schemes, referred to as the uniform-cyclic coding and the uniform-acyclic coding, respectively, are devised for discriminating the range-ambiguous echoes. By choosing a proper phase gradient factor, both coding schemes can be used to resolve the range ambiguities. The uniform-cyclic coding scheme presents a little better performance of the range ambiguity suppression, and the uniform-acyclic coding scheme can preserve the coherency of the range-ambiguous clutters. Simulation results have demonstrated the effectiveness of the proposed coding schemes.