Backscatter from snow and ice surfaces at near incident angles

The radar backscatter of natural snow surfaces was measured at 10 GHz and 35 GHz and at grazing angles from
1\deg
to
0.3\deg
. For horizontal polarized radiation the terrain clutter per unit area (m
²
) at 10 GHz of a flat snow terrain decreases from -50 dB at
1\deg
to -70 dB at
0.4\deg
. The return is approximately 10 dB lower for vertical polarized radiation. The terrain clutter was found to depend on the free water content of the snow. The radar cross sections of ice blocks placed on the snow surface is roughly proportional to the square of the area of the ice block facing the radar at 10 and 35 GHz and is approximately 20 dBsm below the return expected for a perfectly reflecting plane surface. At 95 GHz the ice blocks become diffuse reflectors.