应用天文研究组知识库

以强度起伏Gamma-Gamma分布模型为基础,研究月球激光测距自适应光学系统的回波统计性质。建立了包含整个测距光束传播过程的光场强度或回波光子数涨落的完全统计描述即概率密度函数的具体表达式。以此为基础,计算了一般条件和场景下激光测月的回波光子数平均值、起伏方差、概率密度函数、累积概率函数等一系列统计量,从而获得系统性能改善的基本的定量估计。

Based on the Gamma-Gamma distribution of the intensity fluctuation for light propagating in random media, the statistical properties of received photons of a lunar laser ranging (LLR) system are studied, in which an adaptive optics system is equipped to correct the effect of atmospheric turbulence. A completely statistical description, i.e., the probability density functions of the fluctuation of the received photons, is presented which takes into account most of optical processes. On this basis, a series of characteristic quantities of the received photons, including average value, fluctuation variance, cumulative probability function, and so on, are calculated in the general conditions of the atmospheric turbulence. With these characteristic quantities, a performance evaluation of the LLR adaptive-optics system is obtained quantitatively.