Subsurface TomoSAR imaging of the Mittelbergferner glacier in the Austrian Alps

Abstract

In February 2019, as part of the Enceladus explorer (EnEx) project of the German Aerospace Center (DLR), an F-SAR campaign was organized along the Mittelbergferner glacier in the Austrian Alps. One of the goals of this campaign is to analyze the ice-crust through synthetic aperture radar (SAR) tomography (TomoSAR). During the TomoSAR data acquisitions, different experiments were conducted in situ by the University of Wuppertal, in order to retrieve permittivity measurements at different depths. Making use of this information, the aim of this work is to study the capabilities of TomoSAR to detect the subsurface structures in such an environment. The TomoSAR data is to be focused using the super-resolved statistical regularization technique called WISE, which stands for weighted covariance fitting (WCF)-based iterative spectral estimator. Furthermore, we perform multi-looking using the non-local spatially adaptive Beltrami filter, which enhance the estimation of the data covariance matrices, improving the scatterer separation in layover areas thanks to its smoothing and edge-preserving properties.