Method for measuring gravity deformation of large parabolic antenna

Abstract

The invention provides a method for measuring gravity deformation of a large parabolic antenna. The method comprises the following steps that a reference antenna is provided, and a very long baseline interferometer is formed by the reference antenna and a measured antenna; the reference antenna is enabled to be constantly aligned with a radio source and the measured antenna performs scanning around the radio source so that the reference antenna and the measured antenna are enabled to respectively receive radio source signals transmitted by the radio source; signal processing is performed on the two paths of radio source signals received by the measured antenna and the reference antenna so as to obtain the aperture field phase of the measured antenna; when the pitch angle of the measured antenna rotates for a preset angle each time, the aforementioned steps are performed repeatedly so as to obtain the aperture field phase of the measured antenna under the corresponding pitch angle, and the aperture field phase is the aperture field phase corresponding to primary side precision; the change of secondary side position offset of the measured antenna along with the pitch angle is obtained; and the change of primary side shape deviation of the measured antenna along with the pitch angle is obtained. The change of primary side shape deviation and secondary side position offset of the antenna along with the pitch angle of the antenna can be accurately measured.

Description

technical field [0001] The invention relates to very long baseline interferometry, that is, VLBI (very long baseline interferometry) technology, in particular to a method for measuring gravity deformation of a large parabolic antenna based on the VLBI technology. Background technique [0002] Such as figure 1 As shown, the large parabolic antenna mainly includes three parts: a main surface 1 , a secondary surface 2 and a feed source 3 , and the secondary surface 2 is supported on the main surface 1 by a secondary surface support 4 . Since the gravitational deformation of the antenna will lead to a decrease in the working efficiency of the antenna, it has always been a concern of scientific and technological personnel. [0003] The gravity deformation of a large parabolic antenna mainly involves two aspects: the gravity deformation of the main surface and the gravity deformation of the sub-surface support. changes, while the collimation relationship of the main and secondar...

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Problems solved by technology

However, since the geostationary satellites are only distributed in certain positions above the equator, it is impossible to measure the change of the main surface accuracy with all elevation angles for a position-determined antenna under test.

[0009] In addition, the gravitational deformation of the antenna measured by the above three methods is the change of the overall main surface accuracy of the antenna with the pitch angle, and the variation of the antenna main surface shape deviation and the secondary surface position offset with the pitch angle has not been further measured.

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