DInSAR Performance Investigations with the TOPS mode

Abstract:
The TOPS (Terrain Observation by Progressive Scans) mode is characterized by the steering of the antenna from aft to the fore within a burst. This acquisition geometry introduces a large azimuth-dependent Doppler variation, resulting in very stringent coregistration requirements in order to retrieve accurate interferometric products. The methodology in order to process interferometric data stacks requires additional effort to avoid that such phase errors impinge the retrieved information. In this context, this paper presents an analysis to evaluate TOPS performance for subsidence monitoring by means of DInSAR techniques, namely PS and SBAS. In particular, two interleaved time series acquired by the TerraSAR-X (TSX) sensor in TOPS and Stripmap modes, respectively, are used to evaluate and compare the results. Interferometric processing aspects related to the TOPS mode are also expounded, namely the coregistration requirements and the burst mis-synchronization.