Interferometric Processing of Sentinel-1 TOPS Data

Sentinel-1 (S-1) has an unparalleled mapping capacity. In Interferometric Wide Swath (IW) mode, three subswaths imaged in the novel Terrain Observation by Progressive Scans ({TOPS}) {SAR} mode result in a total swath width of 250 km. Sentinel-1 has become the European workhorse for large area mapping and interferometric monitoring at medium resolution. The interferometric processing of {TOPS} data requires however special consideration of the signal properties, resulting from the {ScanSAR}-type burst imaging and the antenna beam steering in azimuth. The high Doppler rate in azimuth sets very stringent coregistration requirements, making the use of Enhanced Spectral Diversity ({ESD}) necessary to obtain the required fine azimuth coregistration accuracy. Other unique aspects of processing {IW} data, such as azimuth spectral filtering, image resampling and data deramping and reramping, are reviewed giving a recipe-like description that enables the user community to use Sentinel-1 {IW} mode repeat-pass {SAR} data. Interferometric results from Sentinel-1A are provided, demonstrating the mapping capacity of the S-1 system and its interferometric suitability for geophysical applications. An interferometric evaluation of a coherent interferometric pair over Salar de Uyuni, Bolivia is provided, where several aspects related to coregistration, deramping and synchronization are analysed. Additionally, a spatial and temporal evaluation of the along-track shifts, which are directly related to the orbital/instrument timing error, measured from the {SAR} data is shown that justifies the necessity to refine the azimuth shifts with {ESD}. The spatial evaluation indicates high stability of the azimuth shifts for several slices of a datatake.     «

Sentinel-1 (S-1) has an unparalleled mapping capacity. In Interferometric Wide Swath (IW) mode, three subswaths imaged in the novel Terrain Observation by Progressive Scans ({TOPS}) {SAR} mode result in a total swath width of 250 km. Sentinel-1 has become the European workhorse for large area mapping and interferometric monitoring at medium resolution. The interferometric processing of {TOPS} data requires however special consideration of the signal properties, resulting from the {ScanSAR}-type...     »