摘要
上行传输光束的闪烁起伏影响星地激光链路的稳定性,而利用时间平滑效应增加光电探测器曝光时间是克服大气闪烁的有效途径之一。考虑曝光时间的平滑效应,分别导出了小天顶角和大天顶角下的时间平滑因子表达式,在此基础上,分析了接收终端离地高度和天顶角对时间平滑效应的影响。研究结果表明,不管是大天顶角还是小天顶角下的上行传输光束,通过增加探测器的曝光时间都可以大大减少起伏强度,提高瞄准捕获跟踪链路的稳定性。研究结果还表明,随着接收终端离地高度和天顶角的增大,大气闪烁时间平滑作用降低。
Extending the exposure time of photoelectric detectors based on time-averaging effects is one of the effective ways to mitigate the extension of an atmospheric scintillation and to reduce the effect of the atmospher- ic scintillation of uplink optical beams on the reliability of satellite-ground laser links. In consideration of the time-averaging effects of exposure time, the expressions for time-averaging factors for large zenith angles and small zenith angles are derived, respectively. Based on the above, the effects of zenith angles and the heights from ground to an optical transmitter on the time-averaging are analyzed. Analyzed results show that extending the exposure time can mitigate the extension of the atmospheric scintillation of uplink optical beams and can improve the stabilities of the Pointing, Acquisition and Tracking （PAT） links. The results also show that the extension of the time-averaging effects decreases with the increases of the zenith angles and the heights from ground to the optical transmitter.
出处
《中国光学与应用光学》
2009年第3期190-194,共5页
Chinese Optics and Applied Optics Abstracts
