| 摘要: |
| 星地通信背景下，P波段信号在穿越大气到达地面阵列的过程中，受到电离层效应的影响，其波达方向（Direction of Arrival,DOA与极化角均发生改变，因此现有DOA-极化联合估计算法得到的估计值与真实值之间存在误差。为解决此问题，从DOA和极化角两个方面分别进行校正。首先考虑电离层折射效应，建立电离层信号传播模型，以此为基础提出俯仰角误差修正方法。其次针对电离层法拉第旋转（Faraday Rotation,FR效应，分析法拉第旋转角（Faraday Rotation Angle,FRA对信号极化的影响，根据地面目标散射过程，提出两种基于散射矩阵的FRA估计方法。通过仿真实验可知，所提方法可以准确计算P波段信号俯仰角修正值与FRA，在一定条件下，将俯仰角估计精度提高约0.1°，FRA估计精度提高近1°，从而实现DOA与极化角的校正。 |
| 关键词: 星地通信 P波段信号；电离层效应；DOA校正；俯仰角修正；FRA估计 |
| DOI：10.20079/j.issn.1001-893x.240410001 |
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| 基金项目:中央高校基本科研业务费专项资金项目(2042019K50264,2042019GF0013,2042020GF0003;国防科技技术预先研究基金(61404130132;湖北省自然科学基金(2014CFA093; |
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| Correction of Ionospheric Effects on DOA-polarization Estimation of Spatial Signal |
| SUN Jialina,CAI Li b,XIONG Ran,LYU Shengjie,ZHAO Mengkui,GAO Huotaoa |
| (1a.School of Electronic Information;1b.School of Electronical Engineering and Automation,Wuhan University,Wuhan 430072,China;2.Unit 32382 of PLA,Wuhan 430311,China;3.Station 2021 of National Radio and Television Administration,Qiqihar 161006,China;4.Mingfei Weiye Technology Co.,Ltd.,Wuhan 430070,China) |
| Abstract: |
| In satellite-to-ground communication,during the process of P-band signal crossing the atmosphere to reach the ground array,its direction of arrival(DOA and polarization angle are changed by ionosphere effects.Therefore,there is an error between the estimated values obtained by the existing DOA-polarization estimation algorithm and the real values.In order to solve the problem,corrections are made from the aspects of DOA and polarization angle.Firstly,considering the ionospheric refraction effect,a signal propagation model of ionosphere is established,based on which a correction method for pitch angle error is proposed.Secondly,regarding the Faraday rotation(FR effect of ionosphere,the influence of Faraday rotation angle(FRA on signal polarization is analyzed,and two estimation methods of FRA based on scattering matrix are proposed according to the process of ground target scattering.Simulation results demonstrate that the proposed methods can accurately calculate the correction value of pitch angle and FRA of P-band signal.Under certain conditions,the pitch angle estimation accuracy is improved by about 0.1°,and the FRA estimation accuracy is improved by nearly 1°,so the correction of DOA and polarization angle is realized. |
| Key words: satellite-to-ground communication P-band signal ionospheric effect DOA correction pitch angle correction FRA estimation |
