Deformation measurement by single spherical near-field intensity measurement for large reflector antenna

Abstract This paper presents a new method to obtain the deformation distribution on main reflector of an antenna only by measuring electric intensity spherical surface with focal point as center sphere, regardless phase. Combining differential geometry theory geometric optics method, this has derived deformation-intensity equation relate near-field directly. Based finite difference (FDM) and Gauss-Seidel iteration, been calculated from simulated geometrical (GO) physical (PO) methods, respectively, relatively small errors, which prove effectiveness proposed in paper. By means it is possible measure scanning single hemispherical whose area about 1/15 aperture. The measurement needs plane wave at any frequency incident wave, that both signals outer space satellite far-field artificial beacon could be used sources. can realized no matter what attitude elevation angle because size hemisphere are changeable.