Thickness profiling of freshwater ice using a millimeter-wave FM-CW radar

A prototype broadband millimeter wave (26.5 to 40 GHz) FM-CW radar employing digital signal processing techniques has been developed for profiling the thickness of freshwater ice. The radar was tested at elevations of up to 7 m above ice surfaces and at speeds up to 40 km/h both from a surface vehicle and a helicopter. The thickness of pond and river ice sheets between 3-cm and 35-cm thick with and without fresh snow cover and minimal surface roughness showed direct correlation with borehole thickness measurements. Losses due to volume scattering by imbedded air bubbles did not significantly affect system capability to discern the air/ic and ice/water scattering boundaries.<
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