電波ホログラフィ法を用いたパラボラアンテナの鏡面精度測定のシミュレーション(シミュレーションの世界)  [in Japanese] Simulation of Antenna Surface Measurements Using Radio Holography  [in Japanese]

Large reflector antennas have been used for millimeter-wave astronomical observation. Improvements in surface accuracy as well as pointing accuracy of these antennas are one of the most important technical problems. For this reason, improvements in the accuracy of surface measurements are necessary. Recently, radio-holography has been used universally for the surface measurements of large antennas. In this method, surface error is obtained from the measurements of far field patterns. However, pattern measurements are influenced by system noise and propagation phenomena such as atmospheric phase fluctuation and clutter from the ground. In order to estimate the influence of pattern measurement errors on antenna surface measurements, a simulation method using a radio holographic technique is often used. In the first part of this paper, the principle of radio holography is presented. In the second part, simulation examples of radio holographic technique are demonstrated, and the influence of pattern measurement errors on determination of aperture field distribution is explained.