Impact of a Thin Inhomogeneous Snow Layer on a Microwave Corner Reflector RADAR Cross Section: Consequences for Spaceborne Remote Sensing

The dramatic reduction in microwave RADAR corner reflector backscattered power when coated with even a thin layer of snow is investigated, and the impact on spaceborne RADAR remote sensing in polar regions is assessed. Time series over two years of Sentinel-1 measurements in Spitsbergen (Arctic Norway, 79°N) are interpreted in view of this analysis. The refraction of the incoming microwave beam prevents the the backscattered signal from reaching the monostatic RADAR is reproduced in the laboratory controlled experiments demonstrating that low-loss dielectric layers not parallel to the corner reflector conducting sides are the cause of the signal loss.