大口径天线主反射面面形快速摄影测量方法研究

Rapid photogrammetry method for large-aperture antennamain reflector surface

本文针对110 m口径全可动射电望远镜(QiTai Radio Telescope, QTT)全工况下主反射面面形快速高精度测量问题提出了一种基于图像传感器的快速摄影测量方法.该方法将天线主反射面分成16个测量单元,通过每个测量单元的不同焦距的两台相机测量反射面上固定靶标点的像素偏移量,并根据像素偏移量与天线反射面法向偏差之间的关系计算出反射面的变形量.通过优化确定了每个测量单元靶标点的数目,分析了面形测量精度影响因素,确定了每个测量单元上不同焦距的两个相机的安装位置和焦距等关键参数.该方法可以提高测量效率和精度,为大口径天线反射面快速测量提供了一种新的解决方案.

This paper proposes a rapid photographic method based on an image sensor for the rapid and high-precisionmeasurement of the main reflector surface of the Xinjiang QiTai 110-m Radio Telescope under all operating conditions.This method divides the main reflector surface into 16 measurement units. Two cameras with different focal lengths areemployed to measure the pixel offset of fixed target points on the reflection surface of each measurement unit. Further,the reflection-surface deformation is calculated based on the relationship between the pixel offset and the normaldeviation of the antenna reflection surface. The number of target points in each measurement unit is optimized, and thefactors affecting the accuracy of the surface-shape measurement are analyzed to determine the key parameters, includingthe installation position and focal length of the two cameras with different focal lengths on each measurement unit. Thismethod improves the measurement efficiency and accuracy and provides a new approach for the large-aperture antennareflector-surface measurement.