140-GHz Scatterometir System And Measurements Of Terrain

The goal of the University of Michigan millimeter-wave radar program is to characterize terrain scattering at 35, 94, and 140 GHz. The 140-GHz channel of a truck-mounted scatterometer system has recently been added to give the full desired operating capability. Two injection-locked 45.33-GHz Gunn oscillators use triplers to supply the up. and down-converters. Full polarization capability is obtained through the use of rotatable quarter-wave plates. Real-time signal processing and data eduction takes place in an HP 8510A automatic network analyzer on the truck-mounted platform. Sample measurements of millimeter-wave radar backscattering from vegetation and snow are given.