The continuous melting of the ice at the Earth continental polar caps highlights the importance of an exhaustive study of the properties of the ice subsurface targets in order to provide a reliable analysis of their past and future evolution. Such study can be efficiently performed by automatically analyzing radargrams of the ice cross section acquired by radar sounder (RS) instruments. In this letter, we propose an automatic technique for a large-scale detection of the ice subsurface targets and the estimation of their properties (e.g., layered area thickness and bedrock scattering area) from radargrams acquired by RS operated at the Earth continental polar caps. This is done by using the parameters of the RS acquisition system combined with the output of an automatic image segmentation algorithm. The segmentation operation is applied to the radargrams after a preliminary processing phase aimed to emphasize the relevant subsurface targets. The segmentation criterion considers the radar signal backscattering properties and a model of the spatial distribution of the investigated targets that takes into account the effects of the wave propagation though the subsurface. Experimental results obtained on real radargrams acquired by an airborne RS in Antarctica confirm the effectiveness of the proposed technique.