哨兵卫星采用TOPS模式成像,为确保影像干涉相位偏差小于3°,方位向配准精确度需达到0.001个像素。本文论证了哨兵卫星精密轨道条件下进行几何配准即可达到较高的配准精度,满足增强谱分集进行方位向残余偏移量估计的前提条件,并基于DORIS软件实现哨兵卫星TOPS模式影像的几何配准和增强谱分集优化配准处理。地表方位向形变等信号可导致Burst干涉图之间发生相位跳变,并对增强谱分集估计几何配准残余偏移量时产生干扰,本文开展了相关的理论分析和数据处理试验,提出粗差探测方法消除相位跳变对增强谱分集配准的干扰。
The TOPS imaging mode is the default operation mode of Sentinel-1 satellite,an overall azimuth coregistration accuracy of better than 0.001 pixels is required for this configuration in order to achieve the interferometric phase bias is less than three degrees.Based on the high accuracy of Sentinel-1 orbital information,this paper demonstrates a sufficiently high coregistration accuracy is able to be achieved by geometrical coregistration algorithm,which satisfies the pre-requirement for estimating the residual coregistration error by enhanced spectral diversity method.Based on DORIS open source software,a coregistration approach for Sentinel-A TOPS mode is implemented by an algorithm of geometric prediction of the shifts using precise orbit information,and an improvement on coregistration processing is achieved by enhanced spectral diversity.An interferometric phase jump between two Bursts could be caused by surface deformation in azimuth direction,and introduce a disturbance when estimating the residual coregistration error by enhanced spectral diversity method.In this paper,based on related theory analysis and real data processing test,an outlier detection estimation method is proposed to reduce the disturbance of enhanced spectral diversity coregistration method,which is caused by phase jumps.