高分辨率宽测绘带Scan SAR压缩感知成像算法研究

Research on High Resolution Wide Swath Scan SAR Imaging Algorithm Based on Compressive Sensing

高方位向分辨率和宽测绘带对合成孔径雷达(Synthesis Aperture Radar,SAR)系统设计提出了矛盾的要求。为获得高分辨率宽测绘带地面图像,提出了一种基于扫描模式SAR(Scan SAR)及压缩感知(CompressiveSensing,CS)理论的解决方法。Scan SAR可获得宽测绘带,然而各子测绘带方位向照射不完整,导致了低的方位向成像精度。所提出的方法首先对子测绘带数据进行方位向补零,并完成距离压缩和距离徙动校正;在方位向有效数据行中进行随机取样构成新的数据矩阵;根据取样指标集构建合理的重建矩阵,通过ROMP算法重建出完整的方位向点目标位置信息;通过子测绘带图像拼接,即可获得高分辨率宽测绘带地面图像。仿真结果表明了所提出方法的有效性。

High azimuth resolution and wide swath pose contradicting requirements on system design of synthesis aperture radar （SAR）. In order to obtain high resolution and wide swath ground images, a possible solution based on Scan mode and compressive sensing theory is proposed in this paper. The Scan SAR mode can get wide swath, while the azimuth reso- lution of the sub-swath is low because of the incomplete azimuth illumination. The main processing steps of the proposed method include： the sub-swath data is zero padded firstly followed by the range compression and range cell migration correc- tion; new data matrix is obtained by random selecting the effective azimuth rows; according to the random selection index set, a reasonable reconstruction matrix is built, which is used to reconstruct the targets＇ azimuth positions information with ROMP algorithm; the combination of the sub-swath images provides the high resolution and wide swath ground image. The simulations verify the validity of the proposed method.