For issues of temperature gradient and deformation of the primary reflector of large radio telescope under sunshine, a complete test system consisting of temperature measurement and surface accuracy estimation is established. Employing thermal infrared imager under the specific test condition, the temperature distribution of primary reflector at different time is obtained as well as the largest temperature difference of 7.8℃. The surface accuracy of primary reflector is estimated by holography with largest error of 0.33 mm, which is caused by temperature variation. It is shown that the temperature greatly affects surface accuracy of primary reflector. As a result, we can monitor the real-time temperature of primary reflector and adjust the panel to improve surface accuracy utilizing the reasonable test system.%针对大口径射电望远镜主反射面在日照作用下产生温度梯度及形变问题,建立了完整的温度测量及精度评估的系统.在特定的测量条件下,利用红外热像仪测量了望远镜主反射面的温度,获得了不同时刻的温度分布情况,并得到最大温差为7.8℃C.采用全息法分析主反射面的精度变化情况,得到由于温度变化导致的最大误差为0.33 mm.结果表明:温度对望远镜主反射面的精度影响较大,需采取合适的测试系统实时监测温度,并调整主反射面板以提高精度.
展开▼
