地基空间目标监视雷达大气折射误差修正方法研究

Atmospheric refraction error correction approach for ground-based space-target surveillance radar

大气介质垂向非均匀分布会使穿行其中的电磁波发生折射现象,尤其是其中的对流层和电离层,可造成电磁波传播延迟及路径弯曲,进而导致地基空间目标监视雷达测距和测角误差。本文基于射线追踪法实现了大气折射误差建模,推导了雷达测距和测角误差关于大气折射指数垂向分布的精确表达式,并详细阐述了地基空间目标监视雷达大气折射误差修正原理及流程,相比于传统的误差近似模型及修正方法,本文所提出的误差模型更准确、修正方法更有效。基于对流层和电离层模型获取大气折射指数垂向分布特性曲线,进行大气折射误差数值仿真,结果表明,本文方法在大气分层不同间隔取值下的误差补偿精度更高、性能更稳健,特别是在低仰角情况下,其性能优势更加明显。

The vertical inhomogeneous distribution of the atmospheric medium can cause the refraction of propagating electromagnetic waves.In particular,the troposphere and ionosphere can lead to the delay and path bending of electromagnetic wave propagation,and thus cause errors of the measured range and angle for the ground-based space-target surveillance radar.In this paper,the model of the atmospheric refraction error is established based on the ray-tracing method.The accurate expression of the measured range and angle errors with regard to the vertical distribution of atmospheric refraction index is derived,and the principle and procedure for correcting the atmospheric refraction error of ground-based space-target monitoring radar is described in details,compared with the traditional error approximation model and correction method,the proposed error model is more accurate and the correction method is more effective.Based on the tropospheric and ionospheric models,the curve of vertically distributed characteristics of the atmospheric refraction index was calculated,and the numerical simulation of the atmospheric refraction error was carried out.The results show that the proposed method in this paper has higher error compensation accuracy and more robust performance at different intervals of atmospheric stratification,and the performance advantages are more remarkable in the case of low elevation.