A preliminary study on the multitemporal analysis of cryosphere radar sounder data

Radar Sounder (RS) data contain information on subsurface geology and are analyzed mostly with automatic techniques on single-pass acquisitions. A few preliminary studies on multitemporal RS data acquired on the cryosphere focus on possible advances in ad-hoc data acquisition strategy and ice-sheet monitoring, such as the percolation zone. However, challenges related to data corregistration and the inherent characteristics of the target hinder the multitemporal analysis. This paper analyzes bi-temporal radargrams with partially overlapping footprints (thus showing information from neighboring geographical areas) in the cryosphere and defines a strategy to estimate candidate changes. The paper proposes projecting and locally corregistering the radargram pairs at different depths to identify the expected changes due to glacier displacement and snow accumulation. Comparing the corregistered radargrams, we identify candidate unexpected changes in the ice sheet morphology that glaciologists should further validate. The proposed method is validated on several radargram pairs acquired by MCoRDS-3 in Antarctica in 2014 and 2016.