Terrain return measurements at X, K>inf/inf<, and K>inf/inf<band

The back scattering from many different types of terrain has been measured at frequencies of 10, 15.5 and 35 KMC using both vertical and horizontal polarization. The average radar cross section of the terrain <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">σ</tex> has been plotted as a function of incidence angle for the three frequencies. Seasonal changes of vegetation covered terrain, effects of rain, and various types of snowcover are shown as functions of incidence angle, frequency, and polarization. Due to the large quantity of data that have been collected and the accuracy of the data ( <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">± 1</tex> db) certain pertinent parameters that affect the magnitude of the return have been determined. These parameters are: surface roughness, incidence angle, polarization, complex dielectric constant of the terrain, and frequency.