Phase Unwrapping of Multi-Channel Synthetic Aperture Radar: Application to the TanDEM-X Mission

Abstract

The contribution of this thesis is the design and development of a new method which combines bistatic high-resolution interferometric data in order to perform a correct and accurate phase unwrapping on a huge amount of data. This is especially dedicated to the TanDEM-X Mission. The Dual-Baseline Phase Unwrapping Correction (DB-PUC) framework addresses this challenge by correcting errors that occurred during the single-baseline PU procedure. It benefits from the additional information available through the differential interferogram and the stereo-radargrammetric phase. The former is used to correct the ambiguity bands of the misestimated unwrapped phases. The latter enables the assessment of the differential unwrapped phase and the correction of its potential errors region-wise. The region-wise correction of the integer number of cycles allows it to be less sensitive to noise and possible temporal changes. The DB-PUC framework is used during the operational processing (or re-processing) of the TanDEM-X acquisitions, which are used for the generation of the final global DEM. The second global coverage has been unwrapped with the proposed approach with a success rate of 96.5%.