94 GHz Radar Backscatter Characteristics of Alpine Glacier Ice

Measuring the radar backscatter characteristics of glacier ice at different frequencies and incidence angles is fundamental to predicting the glacier mapping performance of a sensor. However, such measurements at 94 GHz do not exist. To address this knowledge gap, we collected 94 GHz radar backscatter data from the surface of Rhônegletscher in Switzerland using the 2nd generation All-weather Volcano Topography Imaging Sensor (AVTIS2). We determine the mean normalised radar cross section \(\left(\sigma^0_{\text{mean}}\right)\) to be -9.9 dB. The distribution closely follows a log-normal distribution with a high goodness of fit (R2=0.99) which suggests that radar backscatter is diffuse and driven by surface roughness. Further, we quantified the uncertainty of AVTIS2 3D point clouds to be 1.30-3.72 m, which is smaller than other ground-based glacier surface mapping radars. These results demonstrate that glacier surfaces are an efficient scattering target at 94 GHz, hence demonstrating the suitability of millimeter-wave radar for glacier monitoring.