针对大气气溶胶粒子的时延效应影响激光测距精度的问题,利用双频互相关函数,推导了离散随机介质中激光程差的计算公式,建立了激光程差与粒子浓度、粒子直径等常规参数间的联系。在此基础上,提出了计算由大气气溶胶粒子的时延效应所引入的激光程差的方法,并根据气溶胶和云雾的光学特性(OPAC)气溶胶模式,计算了卫星对地激光测距时,大气气溶胶粒子所造成的激光程差。结果表明,当激光波长为1064 nm,气溶胶粒子的模式半径大于0.25 μm时,随着模式半径的增大,其造成的激光程差逼近4.6 cm,在毫米乃至亚毫米级激光测距精度要求下,必须对其进行修正。

Time delay of atmospheric aerosol particles and its effect on the path difference of laser were discussed. Using two-frequency mutual coherence function,the equation of path difference in the discrete random medium was obtained and the relation between the path difference with the number density and diameter of particle was established. A new method for calculating the path difference caused by time delay of aerosol particles was presented,and the path difference was calculated by using typical modes provided by optical properties of aerosols and clouds (OPAC) package in satellite laser ranging. Results show that,when the wavelength of laser is 1064 nm and the mode radius of aerosol particles is more than 0.25 μm,the path difference is approaches 4.6 cm with the mode radius increasing;when the millimeter and even sub-millimeter precision of satellite laser ranging is required,the path difference induced by time delay of atmospheric aerosol particles should be corrected.