Relations of Site Effects to Statistical Gain Characteristics of Radar Antennas

In this paper, the results of a study of site effects on the clear-site Fraunhofer zone statistical gain characteristics of several radar antennas are presented. The study was based on two types of site-effects tests. The first type of test was concerned with the illumination of objects in the immediate vicinity of the antenna under test to show that site effects may depend on the clear-site statistics of the receiving antennas under test, on the geometrical configuration of the objects, and on the position of the objects relative to the transmitting and receiving antennas. The second type of test was concerned with the illumination of objects in the distant surroundings of the antennas under test to determine how the frequency, beamwidth, and clear-site median gain of the antennas are related to site effects.