EFFECTS OF SPATIAL INHOMOGENEITIES AND MICROWAVE EMISSION ENHANCEMENTIN RANDOM-MEDIA - AN EXPERIMENTAL-STUDY

The effects of spatial distribution of the scattering elements on micr owave emission from random media have been investigated using an exper imental model composed of long, thin vertical dielectric cylinders on a reflecting screen, The measurements have been carried out at 10 and 37 GHz, H, V polarizations and different nadir and azimuth angles, Ran dom ''uniform'' and ''cluster'' distributions as well as periodic ''ro w'' configurations with different volume fractions have been studied, When the cylinders are distributed in nearly circular clusters or in p arallel rows significant emission enhancement with respect to uniform distribution is detected at 10 GHz and incidence angle lower than 50 d egrees, whereas, at 37 GHz the emission is lower for clusters and stro ngly dependent on azimuth angle for the ''row'' configuration.