压缩感知SAR成像中的运动补偿

摘要

由于其具有压缩采样特性,压缩感知在高分辨SAR成像技术中得到了广泛应用.然而作为一种参数化的成像方法,基于压缩感知的成像方法对位置误差非常敏感.位置误差会造成图像偏离真实位置、散焦、甚至根本不能成像.该文针对SAR压缩成像系统中存在的运动误差,分析了平台非理想运动对回波信号的调制机理和运动相位误差对信号稀疏表征的影响,提出了基于传感器测量数据进行运动补偿的压缩感知SAR成像方法,通过在稀疏矩阵中引入附加项完成空不变运动误差的补偿.该方法不仅能以少量的测量孔径和测量数据获得重建目标空间的足够信息而且能有效降低运动误差对成像质量的影响,实现高分辨成像.%Because of its compressed sampling property, Compressive Sensing (CS) has wide application to high resolution imaging. But as a parametric imaging method, CS based imaging methods are sensitive to position error. Position error may cause defocusing, range migration, or even can not imaging. This paper concerns the analysis and compensation of trajectory deviations in airborne spotlight Synthetic Aperture Radar (SAR). A motion compensated CS SAR imaging scheme is proposed based on the sensor measured data. An additional item is introduced into the sparse matrix to achieve the compensation of space invariant motion error. This method can not only get enough information for imaging using few measure position and data, but also reduce the affection of motion error on image quality, achieve high resolution imaging.