| With the continuous development of some country in the fields of astronomy, communications and deep space exploration, the technology of the related areas has developed rapidly. And large reflector antenna plays a crucial role in those fields. Large reflector antenna develops in the direction of large diameter and high frequency to meet the situation that the detection range increase continuously, the requirements of signal collection and emission improve continuously. These trends make that large reflector antenna need high precision when they are designed and manufactured. In addition, the performance guarantee of large reflector antenna is a major research difficult during service. At the same time, the most of large reflector antennas existing are built in the border areas of countries. The environment conditions in these areas are severe, and the climatic conditions are extreme, so how to compensate the electrical performance decline of the antenna caused by the environmental factor is a challenging task. Therefore, in this paper, the influence of thermal deformation works on the beam pointing of reflector antenna are analyzed and studied. And a compensation method is proposed. Besides, it can be a system with application value in practical engineering if the compensation method is combined with temperature collection of the antenna structure, temperature field inversion and the compute of thermal deformation. The main works are as follows:(1) The influences of deformation of main reflector, the lateral movement of the feed phase center, the rotation and the lateral movement of sub-reflector on antenna beam pointing were analyzed respectively. And the method of calculation related has been given.(2) The several parts of the compensation system used for thermal deformation of large reflect antenna including temperature collection of the antenna structure, temperature field inversion and the compute of thermal deformation are introduced.And the optimal layout of temperature sensors and a variety of different interpolation methods that using a small number of temperature sensors to inverse temperature field of entire field are analyzed. In addition, the fast calculation method of thermal deformation has been studied to obtain a fast matrix algorithm for computing antenna thermal deformation.(3) Since the main surface deformation needs to be fitted when the antenna pointing error is calculated, so least squares fitting for standard reflector antenna and piecewise fitting for shaped reflector antenna are introduced. In addition, the whole compensation system of thermal deformation has been verified in engineering.(4) Due to the huge structure of large reflector antenna, the compensation system mentioned above will take a long time when it makes calculation. So it can't meet the requirement of time that spent in adjusting the pointing of the antenna. In order to solve this problem, the method of database matching is proposed. In addition, some problems existing when it is applied in practical engineering are summarized, and improvement measures have been proposed to solve some of the problem. |
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