应用天文研究组知识库

大气湍流的倾斜扰动会导致光束在通过大气后到达角发生起伏。对于激光测距、激光导引星等应用场合,激光分别在发射和接收时两次通过了湍流大气。激光收发望远镜几何布局方式的不同会引起激光发射和接收光路中的倾斜相关性出现差异,最终影响接收望远镜探测到的激光到达角起伏。从激光收发望远镜布局的一般几何模型出发,利用Zernike多项式波前展开,给出了受大气湍流影响的分离孔径倾斜相关函数。分析了收发共光路与非共光路情况下,不同的几何限制导致的光束到达角起伏相关性变化。最后,讨论了不同的激光收发望远镜的几何布局对接收望远镜探测到的光束到达角起伏的影响。

Tip-tilt disturbance of atmospheric turbulence leads to the angle-of-arrival fluctuations when a beam is propagating through such an atmosphere. The laser beam is propagating through the turbulent atmosphere twice in the cases of satellite laser ranging and laser guide star. Different locations of geometric layouts of laser transceiver lead to the difference in correlation of tip-tilt fluctuations between laser launch and receive paths, and affect the variations of angle-of-arrival fluctuations in the end. Based on the geometry of laser transceiver, the tip-tilt correlation between two separated apertures is developed by using the wavefront expansion on the Zernike polynomials. The changes of the tip-tilt correlation due to the geometrical limit of common optical path system and non-common optical path system are analyzed. Finally, the impacts of geometric layouts of the different laser transceivers on the angle-of-arrival fluctuations are discussed.