大气湍流对天文望远镜光电导行精度的影响  

Influence of Atmospheric Turbulence on the Accuracy of Astronomical Telescope Auto-Guiding System

作　　者：柳光乾[1,2] 杨磊[1] 邓林华[1,2] 李银柱[1] 刘忠[1] 

机构地区：[1]中国科学院云南天文台,云南昆明650011 [2]中国科学院大学,北京100049

出　　处：《光学学报》2013年第1期7-11,共5页Acta Optica Sinica

基　　金：国家自然科学基金(11003041;11103077)资助课题

摘　　要：讨论了由大气湍流造成的望远镜导行误差,这一误差将给望远镜光电导行的精度带来较大影响。其中使用单点源目标的导行精度受限于大气相干长度和大气相干时间,而多点源目标及面源的导行精度还与湍流随高度的变化有关。通过分析和仿真(数值模拟)结果表明,现代天文观测必须考虑大气湍流对光电导行精度的影响。通过延长曝光时间可以有效降低湍流大气的影响,同时也降低了光电导行的反馈控制频率。当导行信标为多星或面源则可在一定程度上降低高层大气湍流带来的光电导行误差,从而可以适度减少光电导行曝光时间,提高其反馈控制频率。Telescope guiding error caused by atmospheric turbulence is discussed,which affects significantly the accuracy of telescope auto-guiding system.Guiding precision of a single point source target is limited by the atmospheric coherent length and coherent time,and several point source targets and extended celestial bodies guiding precision also have relation to the turbulence height.Furthermore,analysis and simulation（numerical simulation） results show that modern astronomical observations must consider the influence of atmospheric turbulence on the accuracy of the auto-guiding system.Extending the exposure time can reduce the influence of the turbulent atmosphere,but also reduce the feedback control frequency of the auto-guiding system.The guiding beacon of several stars or extended source can reduce partly auto-guiding error caused by high-layer atmospheric turbulence,which can appropriately reduce the exposure time of the auto-guiding system,and improve its feedback control frequency.

关 键 词：大气光学 天文望远镜 跟踪精度 大气相干长度 等晕区 数值模拟 

分 类 号：P427.1[天文地球—大气科学及气象学]