一种基于相位校正的InISAR图像配准新方法

摘要

Aimed at the image registration problem in inteiferometric inverse synthetic aperture radar ( InlSAR), the causation of the offset between two ISAR images for different interferometric antennas along one baseline was analyzed. Then a quantitative analysis of the offset and its influence on the following inteiferometric processing was discussed. It was shown that the sub-pixel offset in the down-range direction and the pixel offset in the Doppler (cross-range) direction induced mismatching of two ISAR images. A novel image registration method based on phase correction was proposed to solve the mismatching problem in InlSAR imaging. Simulation results demonstrate that the offset between two ISAR images is compensated effectively when the proposed new method is used, achieving an improvement of the quality of three-dimensional (3-D) image consequently.%针对InlSAR三维成像中的图像配准问题进行研究,从理论上推导了同一基线上两干涉天线之间图像失配准的原因,并定量分析了图像失配准量对后续干涉处理的影响.研究表明,初始时刻同一基线上两干涉天线间的波程差引起两幅ISAR图像距离方向的亚像素级失配,而成像积累时间内两干涉天线波程差的变化量则引起两幅ISAR图像多普勒方向的像素级失配.针对干涉天线图像间的二维失配问题,提出了一种基于相位校正的图像配准新方法.该方法从参考距离选取的角度出发,对辅助接收天线的回波信号进行相位校正,补偿了由干涉天线间的位置差异引起的两幅ISAR图像之间的失配准量,完成两幅图像间的精确配准,得到反映目标真实尺寸的三维像.