1.2m望远镜自适应光学系统中激光导引星聚焦非等晕性

Focus anisoplanatism for 1.2 m telescope laser guide stars in adaptive optics system

分析了云南天文台1．2m望远镜61单元自适应光学系统上如果配置激光导引星，由信标上方以及信标下方采样不完整性造成的聚焦非等晕性误差大小。为了减小聚焦非等晕性误差，可以采用投射多重信标方法。同时讨论了多重信标方法造成的信标位置测量误差和圆锥倾斜误差两种额外误差，理论分析并数值模拟了当投射2～5颗钠导星和瑞利导星时其误差大小。结果表明：随着导星高度以及导星数的增加，该方法可以有效地减小聚焦非等晕性误差，对于钠导星其误差小于1rad^2。

A precise simulation the focus anisoplanatism error of Yunnan observatory 1.2 m 61-element laser guide star adaptive optics system, which caused by laser beacon at a finite range travels a different path than does the light from natural star at a infinite range. This error can be eliminated by use of laser guide stars. However, there are two sources of error limit multiple beacon adaptive optical system, beacon position measurement error and conic tilt error. Analysis the two errors when project two to five laser guide stars. The result showed that with the increase of high and number of laser beam, especially the focus aniso- planatism of Na laser guide stars could reduced to 1 rad^2.