大气折射对跟踪天线指向的影响及修正方法

Influence and correction method of atmosphere refraction on tracking antenna direction

本文对对流层大气折射造成的跟踪天线指向误差进行研究。采用三段式指数型模型模拟对流层大气折射率分布状态。对电磁波折射传播路径进行微分建模,区别于传统的近似计算,给出基于地面站和飞机海拔高度以及两者间水平距离的折射误差精确计算公式。最后对跟踪天线仰角误差和飞机天线俯角误差进行修正,给出修正方程,并提出一种改进方法,将误差修正方程进行扩展,用于地面跟踪天线处于负仰角情况下的误差修正问题。利用MATLAB计算在标准大气条件下的误差修正问题,验证上述方法的合理性和可行性。

The influence of the troposphere refraction on the antenna direction is numerically analyzed in the paper. The three-part exponential model is used to simulate the troposphere refractive index. Then, a differential model is set up to describe the refractive path of the electromagnetic wave propagation. Furthermore some functions, based on the altitude of the station, the altitude of the plane and the distance between them, are given, and the refractive error is cal- culated in different from traditional approximate method. At last, the function is brought forward to correct the elevation error of the tracking antenna of earth station and the antenna of the plane, on which an improved method is proposed to solve the error of the tracking antenna of earth station with negative elevation. All the performance of functions above is tested by Matlab in the situation of normal atmosphere.