Angles-of-arrival and tropospheric multipath microwave propagation

A wide-aperture vertical array is described, the function of which is to determine experimentally the angle-of-arrival and amplitude of individual rays during tropospheric multipath propagation. The primary objective is to provide high-resolution estimates both in measured values and in time. Some experimental results are presented indicating that under such conditions, several rays are generated which are separated in angle-of-arrival by a significant amount, consistent with that predicted by ray-tracing. Significant variations in amplitude of the individual components in times in the order of a few seconds are also observed. Some evidence is presented linking the occurrence of deep fast fading to atmospheric buoyancy waves.