应用天文研究组知识库

传统的激光导引星(LGS)由于激光发射与接收光路的限制,导致难以利用激光导引星来探测大气倾斜量变化。其中重要的一个解决方案就是利用辅助望远镜,从侧面对激光导引星进行探测,从观测到的激光导引星带状拖影中提取出大气倾斜信息。随着激光带拖影长度的增加,必然导致其出现非等晕现象。给出了激光导引星带状拖影上两球面波之间的Zernike多项式展开系数角度相关函数。从相关性的角度分析了导引星高度、大气湍流强度以及接收望远镜口径对激光导引星带状拖影的非等晕性的影响。此外,基于激光导引星倾斜探测方案的非等晕限制,给出了Na层激光导引星倾斜量探测方案中的辅助望远镜视场限制。

Traditional laser guide star (LGS) is difficult to detect the variance of atmospheric tilt because of the limitation of laser transmitter and receiver light path. An important solution is to use auxiliary telescopes to detect the LGS from the side, in order to single out the information of atmospheric tilt from the observed LGS strip. It leads to the phenomenon of anisophanatism with the increase of the length of LGS strip. The Zernike coefficient correlations between two spherical waves coming from the LGS strip are developed. From the point of correlation, the effect of the altitude of LGS, atmospherical turbulence and the caliber of the receiving telescope on the anisoplanatism of the LGS strip is analyzed. Furthermore, based on the anisoplanatism limitation of the tip-tilt determination concept, the request of field of view (FOV) of auxiliary telescope to view the sodium LGS is presented.