基于经验电离层模型的短波时差定位理论分析  

Theoretical analysis of shortwave TDOA geolocation based on empirical ionospheric model

作　　者：李琛 周晨[1] 王君明 吕明杰 乔玮 LI Chen;ZHOU Chen;WANG Junming;LYU Mingjie;QIAO Wei(School of Electronic Information,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学电子信息学院,湖北武汉430072

出　　处：《系统工程与电子技术》2023年第7期1911-1919,共9页Systems Engineering and Electronics

摘　　要：在短波波段,信号从辐射源到接收站要经过电离层反射,因此短波时差定位模型包含电离层信息。传统短波时差定位将电离层等效为均匀分布模型,电离层信息的扰动对定位精度的影响较大。本文利用国际参考电离层模型获取电离层的电子密度信息,以数值型三维射线追踪的方法建立起短波时差定位方程并推导了相应的克拉美罗下界(Cramer-Rao lower bound,CRLB)。仿真结果表明,短波时差定位的CRLB在白天低于夜晚,太阳活动高年和太阳活动低年差别不大;在准确获取电离层信息的条件下,电离层的变化对短波时差定位的CRLB影响并不显著。For shortwave,the signal from the radiation source to the receiving station has to be reflected by the ionosphere,so the shortwave time difference of arrival(TDOA)geolocation model includes ionospheric information.The ionosphere is equivalent to a uniform distribution model in traditional shortwave TDOA positioning,and the disturbance of ionospheric information has a great impact on the positioning accuracy.In this paper,the electron density information of the ionosphere is obtained by using the international reference ionosphere(IRI)model,the shortwave TDOA geolocation equation is established by using the numerical three-dimensional ray tracing method,and the Cramer-Rao lower bound(CRLB)of shortwave TDOA geolocation is derived.The simulation results show that the CRLB for shortwave TDOA geolocation is better during the day than at night,and there is no significant difference between high solar activity years and low solar activity years.Under the conditions of accurate acquisition of ionospheric information,variations of the ionosphere does not have a significant impact on the CRLB of shortwave TDOA geolocation.

关 键 词：国际参考电离层模型 数值型三维射线追踪 短波时差定位 克拉美罗下界 

分 类 号：TN011[电子电信—物理电子学]