星载网状天线反射面面型精度测试与分析

Measurement and Analysis of Surface Accuracy of Reflector in Satellite Mesh Antenna

星载网状天线反射面作为大口径天线的重要结构部件,其面型精度直接影响天线的电性能。针对主要由抛物肋板、充气环、张力系统、中心鼓结构构成的网状天线反射面,采用数字摄影测试技术建立了反射面面型精度测试方案,获得了抛物肋板上普通标志点的空间坐标以及与最优抛物面之间的偏差,并开展了反射面面型精度的分析。为了提高网状天线反射面面型精度,提出了分阶段地依据各普通标志点偏差方向和大小调节肋板上节点至地面垂直距离的反射面面型调整方法。在阶段1至4中经过调整之后反射面面型精度分别提高了75.0%、54.3%、36.6%和37.4%,表明该天线面型调整方法的有效性。阶段4中网面的安装大大降低了抛物肋板的面型精度,同时抛物肋板的偏差趋势与阶段2偏差相近,所以前期阶段肋板的调整尤为重要,而反射面抛物肋板上的偏差主要分布于副肋。

The reflector of the satellite mesh antenna is an important structure of the large-aperture antenna,and the surface accuracy of the satellite mesh antenna directly affects the electrical per-formance of the antenna.The reflector of the mesh antenna mainly consists of the parabolic ribs,the inflatable ring,the tension system and the central drum structure.Digital photogrammetric technique was used to establish the test scheme of the surface accuracy of the reflector.The spatial coordinates and the deviations from the optimal paraboloid were obtained along the parabolic ribs.Then the sur-face accuracy of the reflector was analyzed.To improve the surface accuracy of the reflector,a meth-od for adjusting the surface accuracy of the reflector was proposed,in which the vertical distance from the nodes of the ribs to the ground was adjusted in stages based on the direction and the devia-tion of the common mark points.After adjustment from stage1to4,the surface accuracy of the re-flector was improved by75%,54.3%,36.6%and37.4%respectively.The validity of the pro-posed method for adjusting the surface accuracy of the reflector was verified.The installation of the mesh surface in stage4greatly reduced the surface accuracy of the parabolic ribs,and the deviation of the parabolic ribs was similar to that of the stage2.So the adjustment and optimization of the ribs in the early stages are important.The deviation of the parabolic ribs of the reflector was mainly dis-tributed in the secondary ribs.