Ka- and V-band clutter measurements at grazing angle extremes

Measured soil and vegetation surface clutter data has been available in the public literature since the 1970\´s and extensive campaigns have been performed also to record the effects of snow. However, most of those tests were made only at 35 or 95 GHz and excluded very small or very large grazing angles. Our new measurements deal with previously unpublished frequencies and angles and indicate, that the average Ka-hand reflectivity of trees is -10 dB(m2/m2) for grazing angles of 85°-90°, but values as high as 0 dB(m\´/m2) have been found as well. An average ground reflectivity value of -20 dB(mz/m2) has been measured at grazing angle of 3". Additional V-hand experiments suggest that the per endicular reflectivity of pine or spruce forests is -15 dB(m /mz) and give -20 dB(m2/m2) for grass-covered soil at grazing angles of 3\´ and So. Single trees and deciduous hushes seem to have reflectivities up to -10 dB(mz/mz) within this frequency band. Narrower statistical RCS distributions are generally observed at Ka-band than at V-baud regardless of clutter type.