内部振动对30m望远镜三镜的影响

Influence on the 30m Telescope Tertiary Mirror Performance by the Internal Vibration

利用数值方法得到任意形式振动下30m望远镜三镜的光学传递函数,并分析其数值精度.在光学传递函数的基础上引入标准化点源敏感性来表征振动对系统光线中继功能的影响.为了验证理论分析,对于某大口径设备进行实验,采用多个加速度计共同采集数据并合成信号的方法来实现镜面运动信息的解耦与测量误差抑制.结果表明:在内部振源工作的情况下,设备点源敏感性从0.999 96下降到0.999 92;使用二阶巴特沃兹带通滤波器后,对于外部的力输出为0.075N.

The optical transfer function of 30 mtelescope tertiary mirror under arbitrary forms of vibration was obtained by numerical method,and the accuracy was analyzed.The normalized point source sensitivity was introduced to present the influence of internal vibration on the light beam transmit function.To verify the theoretical analysis,a larger aperture telescope was experimented.In the experiment,a multi-accelerometer method was used,the decoupling of the mirror rigid body motion and the constrain of the testing error were realized by data collected by the residual accelerometers.The results demonstrate that,under the influence of the internal vibration source,the normalized point source sensitivity degrades from 0.99996 to 0.99992.After passing the filter the output force is 0.075 N.