基于多维编码信号星载MIMO-SAR的回波分离方法

摘要

Spaceborne multi-input multi-output SAR (MIMO-SAR) system combined with multidimensional waveform encoding can obtain wider unambiguous swath width and higher azimuth resolution than traditional spaceborne SAR system. However, the mount of data of waveform diversity extraction method based on traditional digital beam-forming (DBF) techniques is seriously high and the great receive antenna gain loss from topography occurs with the recent presented scan-on-receive (SCORE) technique. A new waveform diversity extraction approach taking advantages of the SCORE technique via sub-array antennas and posterior space time processing (STP) is proposed in this paper. This approach can reduce the high date rate of SAR systems and the receiveing antenna gain loss from topography in the SCORE technique. Furthermore, this approach remains some useful information of multi-channel in elevation for other applications and it is easy to be realized. Simulation results validate the presented approach is better than the waveform diversity extraction method based on the SCORE technique.%针对基于常规距离向DBF接收技术的回波分离方法存在数据量大的缺点和基于SCORE技术的分离方法受地形影响导致回波接收增益损失严重的问题,提出了一种结合距离向子阵SCORF技术和空时后处理的MIMO-SAR回波分离方法,它不仅可以降低星载SAR系统的数据率,还能减小SCORE技术中接收增益的损失；该方法还保留距离向部分多通道信息,利于其他模式的应用以及工程的实现.仿真结果验证了该方法的有效性,同时其分离效果好于基于SCORE技术回波分离方法.