A Method for the Characterization of the Interior of Pits from Single Spaceborne SAR Images

Pits are depressions in the ground that occur due to the collapse of the surface layer. The characterization from the orbit of their internal structure using optical images is challenging due to uncontrolled illumination geometry. In this letter, we propose a methodology for the characterization of pits' interiors by exploiting Synthetic Aperture Radar (SAR) images. The methodology analyzes the amplitude and range of the radar echoes originating from the pit's interior to determine its geometric characteristics through data inversion. The experimental results demonstrate that a set of bright reflections in the radar image can be attributed to the response of pits' vertical walls and floor. By applying the proposed methodology and interpreting the radar reflections, we are able to derive a geometric characterization (e.g., depth) of a given pit. The retrieved geometric parameters from SAR data of a terrestrial pit denoted as Well of Barhout align well with the ground truth. The findings of this study have implications for both Earth observation and planetary exploration.