V. I. Lavrov, A. V. Kuzovnikov, V. G. Somov

Features of manufacturing of reflectors of large-sized onboard antennas from facilitated coal plastic spokes and a thin mesh current-carrying matter which forms a reflector profile, do not allow spending in land conditions measurement of electric characteristics of onboard antennas with a diameter more than 5 m. In article the technique of measurement of characteristics of large-sized onboard antennas is offered. The technique is based on consecutive performance of some estimations. First of all spend an estimation of achievable accuracy of a profile of a reflector. Then its three-dimensional model to which the feed model is added is under construction. For calculation of peak and phase directional diagram of antenna are set two main sections peak and phase diagrams of orientation of a feed. For approximation three-dimensional directional diagram of antenna are used radial polynomial of Zernike. It is established, that the offered algorithm of approximation three-dimensional directional diagrams of the antenna and its separate sections polynomial of Zernike allows receiving the most exact estimations.