Adaptive Multilooking of Airborne Single-Pass Multi-Baseline InSAR Stacks

Multilooking is a critical task in interferometric synthetic aperture radar (SAR) imaging. While there are many algorithms designed for SAR image pairs and also some first approaches for multi-temporal satellite data stacks, no method suitable to airborne single-pass stacks that typically contain just a small number of multi-baseline acquisitions has been proposed yet. This paper presents an adaptive procedure to determine regions of homogeneous backscattering in heterogeneous scenes such as urban areas. Based on these regions, the complex covariance matrices can be estimated for all pixels in the stack. This step enables the retrieval of all relevant information of the multi-baseline InSAR data set, e.g., despeckled intensity images, interferometric phase observations, and related coherence maps. The denoising efficiency of the proposed method is evaluated and compared to different algorithms. Furthermore, the detail preservation is analyzed in order to prove the validity of the homogeneity assumption.