一种基于频域子带合成的多发多收高分辨率SAR成像算法

A High-resolution Imaging Algorithm for MIMO SAR Based on the Sub-band Synthesis in Frequency Domain

针对传统单通道SAR系统无法同时实现方位向高分辨率和大测绘带宽的不足,该文研究了一种基于多载频LFM波形的方位多孔径MIMO SAR系统,建立了相应的几何模型,详细推导了其回波表达式,并提出了一种基于频域子带合成的MIMO SAR高分辨率成像算法。该算法将方位向多普勒解模糊,改进的距离向频域子带合成和CS成像算法相结合,能够同时实现2维高分辨率和大测绘带宽,且提出的频域子带合成法较传统时域和频域合成法更高效实用。理论分析和计算机仿真结果验证了其有效性。

Considering the contradiction between the azimuth resolution and the swath width for the traditional SAR,a MIMO SAR system with multiple-carrier-frequency LFM waveform is researched.The corresponding geometrical model is built,and the expressions of the echo signals are derived in detail.A novel imaging algorithm based on the sub-band synthetic technology in frequency domain is proposed.This algorithm which integrates the removing of azimuth ambiguities,the synthesis of the sub-band and the CS imaging can realize 2-D high resolution and wide swath simultaneously.And the improved sub-band synthetic algorithm has more efficiency and practicality than the traditional sub-band synthetic algorithms in time frequency domain.The effectiveness of this method is verified with the theoretical analysis and the computer-based simulations.