基于标准大气环境的大气折射率理论模型不能反映实际大气折射率的波动性,针对该问题,提出了一种基于恒星光线偏折的大气折射率估计方法。基于光学卫星的恒星观测数据,分析恒星光线经大气折射发生偏折的现象,建立恒星光线经大气折射后进入光学卫星传感器的光路模型,在分层球形大气的假设下证明该光路模型的对称性。研究一种利用恒星实测光线和恒星理论光线迭代前向反馈的方法,用以估计分层大气折射率。最后,利用光学卫星的恒星观测数据进行有效性验证,计算出的大气折射率与理论大气折射率相符,且能够反映短期波动性。对测试用的恒星实测数据进行处理,结果表明:88%以上的恒星理论视线与实测视线的估计值相差不超过1%,其余部分观测数据估计偏差基本不超过20%。

The theoretical atmospheric refractivity model, which based on the standard atmosphere, fails to reflect the volatility of the actual atmospheric refractivity. To solve this problem, an atmospheric refractivity estimation method is proposed according to stellar light deflection. Firstly, based on the stellar observation data of optical satellite, the stellar light deflected by atmospheric refraction is analyzed. An optical path model of which stellar light enters the optical satellite sensor after being refracted by the atmosphere is established. The symmetry of the optical path model is proved under the assumption of layered spherical atmosphere. Secondly, an iterative forward feedback method is proposed by measuring stellar light and theoretical stellar light, which can estimate the layered atmospheric refractivity. Finally, the method is validated using the stellar observation data. The calculated atmospheric refractivity agrees with the theoretical one, and shows the short-term volatility. The results of the experimental data show that more than 88% of the estimation error between the theoretical sight and the measured one is within 1%, and the remaining is no more than 20%.