| Popis: |
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. |
