Time-series co-registration for Sentinel-1 TOPS SAR Data

• Main Authors: MA Zhangfeng, JIANG Mi, DING Qixuan
• Format: Article
• Language: zho
• Published: Surveying and Mapping Press 2021-05-01
• Series: Acta Geodaetica et Cartographica Sinica
• Subjects: terrain observation by progressive scans; co-registration; coherence; sentinel-1; synthetic aperture radar; enhanced spectral diversity
• Online Access: http://xb.sinomaps.com/article/2020/1001-1595/2021-5-634.htm
• ISSN: 1001-1595; 1001-1595

TOPS mode is the default imaging mode of Sentinel-1 satellites, which requires an overall azimuth co-registration accuracy of 0.001 pixels to ensure that the interferometric phase difference of consecutive bursts is less than 3°. Although the ESD technique is an effective method to correct the azimuth residual shift, the accuracy will decrease due to the abrupt loss of coherence. To solve this issue, this paper presents a method to improve the accuracy of TOPS co-registration by maximizing time-series coherence. The method focuses on selecting interferometric pairs with optimal coherence and simultaneously preserve the temporal network loops by Bellman-Ford algorithm. The improvement of network can reduce the error propagation caused by low coherence during the least-squares adjustment, and therefore improve the performance of ESD estimation. Based on synthetic data and real data covering the Weihe plain, we evaluate the performance of proposed method against the state-of-the-art techniques. The results demonstrate the effectiveness of the proposed method.