Very high-resolution three-dimensional imaging of natural environments using a tomographic ground-based SAR system

This paper concerns three dimensional imaging of volumetric natural environments, such as snow packs and sea ice, using a ground based SAR system and X and Ku bands. The ground-based acquisition system consists of a vector network analyzer and an multi-static antenna system, moved along two orthogonal directions, so as to obtain a two dimensional synthetic array. Tomographic processing techniques, based on the coherent combination of the acquired SAR signals and adapted to the three-dimensional focusing of very high resolution data, are proposed. Specific automatic correction approaches, aiming to compensate for acquisition errors and uncertainties, are developed in order to improve the quality and descriptiveness of the tomograms. It is then shown that three dimensional imaging permits to retrieve the vertical structure of shallow volumetric media at a resolution of few centimeters and to emphasize physical scattering phenomena that cannot be observed from classical two-dimensional SAR data sets.