Millimeter-wave measurements and analysis of snow-covered ground

Initial investigations and analyses have indicated that, although not predicted by present theory, the millimeter-wavelength (MMW) scattering properties of certain types of snow known as metamorphic or refrozen snow can create a problem for the detection of man-made targets. In 1984, researchers from the US Army, the Georgia Institute of Technology, and others carried out the SNOWMAN test program, which was a comprehensive data collection program using 35- and 94-GHz instrumentation radars to measure the backscatter cross section of snow-covered terrain as a function of wavelength, coherent bandwidth, polarization, (for both the incident and scattered waves), and the incidence angle. The radar measurements were supplemented by an extensive ground truth program that provided details of the meteorology and the physical characteristics of the snow cover. The authors describe the data collection procedures, present examples of the results, identify gaps in the data, and suggest additional analyses that could be performed to maximize the utility of the SNOWMAN data base.<>