基于DEM的低相干区SAR干涉图卡尔曼滤波相位解缠算法

摘要

相位解缠是利用干涉合成孔径雷达(InSAR)进行DEM提取和微小地表形变测量的关键技术之一.常规的卡尔曼滤波相位解缠算法在地形平坦区域可以获得可靠的结果,但是在地形起伏较大的区域却容易产生误差的传递,致使其结果无法准确反演地表形变信息.为此,提出了一种基于DEM的SAR干涉图卡尔曼滤波相位解缠算法.该算法借助美国航天飞机测绘任务(SRTM)获得的DEM信息指导SAR干涉图解缠,以提高解缠的速度和精度.通过与常规卡尔曼滤波解缠算法的结果比较分析表明,利用SRTM DEM地形信息指导卡尔曼滤波相位解缠尤其能够提高低相干区域相位的解缠精度.%Phase unwrapping is one of the key technologies for the utilization of Interferometric Synthetic Aperture Radar (InSAR) to conduct DEM extraction and small surface deformation measurement. The conventional Kalman filter phase unwrapping algorithm can obtain reliable results in flat terrain areas, but it will cause error transmission and not make the accurate inversion of surface deformation information in the steep terrain. This paper presents a Kalman filter phase unwrapping algorithm of SAR Interferogram based on DEM. With the DEM topographic information obtained by the U. S. Space Shuttle Radar Topography Mission (SRTM) to guide SAR Interferogram and implement unwrapping, it can improve the speed and accuracy of unwrapping. A comparison with the conventional Kalman filter algorithm shows that the proposed Kalman filter phase unwrapping algorithm can achieve good results, especially in improving unwrapping accuracy in the low coherence region by using the SRTM DEM information to guide unwrapping.