Coherent polarimetric SAR measurements of dihedrals and trihedrals characterizing the propagation properties of a forest canopy

Summary form only given. The HP8753-based radar was used to perform measurements at 200-2000-MHz during the late summer and again in the fall of 1991. The radar, mounted 100 ft above the ground, overlooked a woodlot typical of the forested areas found throughout the central and northeastern USA. This includes such trees as black cherry, sugar maple, American elm, red oak, and bitternut hickory with an average canopy height of 60 ft. In the foreground was located a small 2-ft dihedral used to determine the calibration transfer function of the radar. This, in conjunction with antenna patterns and free space loss compensation, is sufficient to calibrate radar-cross-section measurement of down-range targets concealed in the forest. Located on the forest floor were numerous dihedrals and trihedrals ranging in size from 4 to 8 ft on edge, and the calibrated measurements of these targets provided the means to extract foliage propagation properties of the forest.<>