UNFOCUSED SAR PROCESSING FOR ENGLACIAL LAYER SLOPE ESTIMATION USING RADAR SOUNDER DATA

Radar sounders represent a powerful remote sensing solution to probe icy surface and detect subsurface layers by tracking vertical dielectric discontinuities. These englacial layers are fundamental indicator of the dynamic, rheological, and subglacial configuration of an ice sheet. However, steep layers can disappear when along-track processing is applied to radar sounder data. In this work, we present a novel Synthetic Aperture Radar (SAR) processing technique that aims to enhance the post processing Signal to Noise Ratio (SNR) of subsurface layers and avoiding interference in data processing. The proposed technique uses the phase and magnitude of a single channel RS system in a four step approach, made up of: i) sidelobes weighting, ii) range compression, iii) phase-shifted along-track coherent summation, and iv) multilooking. Additionally, the proposed technique allows the automatic estimation of the slope of layers. The proposed processing method has been validated on airborne radar sounder data acquired in Antarctica, while the slope estimation result is theoretically demonstrated.