Automatic Extraction and Analysis of Ice Layering in Radar Sounder Data

Nowadays, the interest on the development of orbiting radar sounders for the observation of Earth polar areas is increasing. In this context, the analysis of the structure of the ice stratigraphy is of primary importance for the study of the past history and for the prediction of the evPolution of icy environments. However, as proven by planetary missions, orbiting radar sounders provide a huge amount of data. Thus, the development of automatic techniques for the analysis of these data is of fundamental importance for proper data exploitation. In this paper, we propose a novel method for the automatic detection of subsurface linear features from radar sounder data acquired in icy regions showing extended layering. The proposed method allows the estimation of the position of the linear features with subpixel accuracy. Moreover, each detected linear interface is treated as a single object which is completely described by the position of its points, the estimated local width, and the contrast. This allows the direct measurement of geometrical and radiometric parameters (e.g., slope angle and intensity) without the need of further postprocessing steps. This paper also proposes some measurements for deriving from the output of the proposed technique important variables that can characterize quantitatively the properties of the detected linear features (e.g., mean depth and mean intensity) and their distribution (e.g., number and density of layers). The effectiveness of the proposed method is confirmed by the results obtained on several radargrams acquired by the Shallow Radar on the North Pole of Mars.