Measurement of enhanced backscattering from randomly distributed conductive spheres with concentrically different number densities at 60 GHz

The effective utilisation of millimetre-wave radar for precipitation measurements seems to require quantitative evaluation methods of enhanced backscattering from randomly distributed particles. One such method is a computer simulation technique proposed in the literature [Radio Science, 2006, 41, RS6002], a technique that takes into account the spherical wavefront and directivity functions of transmitting and receiving antennas. The effectiveness of this technique has been previously verified by the present authors by comparing laboratory-controlled scattering experiments performed at 60 GHz using cylindrical scattering volumes, where conductive spheres of a monodispersive size are randomly distributed with statistically uniform number densities. In this latest reported work, the effectiveness of this computer simulation technique is further demonstrated for the case where conductive spheres are randomly and non-uniformly distributed with concentrically different number densities.