过电离层电磁脉冲信号的传播参数反演方法与试验研究  

Methodology and experiment study for the derivation of propagation parameters of the trans-ionospheric electromagnetic pulses

作　　者：李宗祥 曹保锋 李鹏 李欣 张雄 魏雍力 王元 王丽华 张天池 李晓 李小强 LI ZongXiang;CAO BaoFeng;LI Peng;LI Xin;ZHANG Xiong;WEI YongLi;WANG Yuan;WANG LiHua;ZHANG TianChi;LI Xiao;LI XiaoQiang(State Key Laboratory of NBC Protection for Civilian,Beijing 102205,China;College of Information and Communication Engineering,Harbin Engineering University,Harbin 150001,China)

机构地区：[1]国民核生化灾害防护国家重点实验室,北京102205 [2]哈尔滨工程大学信息与通信工程学院,哈尔滨150001

出　　处：《地球物理学报》2025年第2期399-412,共14页Chinese Journal of Geophysics

摘　　要：使用多星联合到达时间法定时定位电磁脉冲(ElectroMagnetic Pulses,EMPs)的关键在于精确反演传播参数,并矫正电离层色散效应引起的传播时延.经典的参数反演方法存在抗干扰能力差、拟合结果对初值依赖性强以及无法解析电波双折射信号等问题.为此,提出一种能应对上述不足的过电离层EMPs传播参数反演方法,计算倾斜总电子含量(SlantTotalElectron Content,STEC)和拍频,并确定信号矫正时延后的绝对到达时间.星载宽带电磁脉冲探测器(Wideband Electromagnetic Pulse Detector,WEMPD)轨道高度约500 km、倾角97.5°,探测到478次地基电磁脉冲模拟器信号.观测结果与其他数据综合对比分析发现:当STEC大于10 TECU时,WEMPD反演拍频与固定高度地磁场模型预测结果基本吻合,平均相对误差16.81%;WEMPD反演垂直电子总含量(Vertical Total Electron Content,VTEC)与国际参考电离层模型预测结果一致,平均偏差2.35 TECU;WEMPD反演VTEC与中国科学院全球电离层电子总含量格网具有相同的电离层时变特征表征能力,二者偏差全年保持在10 TECU左右;WEMPD反演STEC高阶效应的显著性与不同时间电离层条件有关,清晨约为傍晚3倍;矫正高阶效应后,WEMPD的定时精度2.34μs,相比矫正前提升约20%.研究结果不仅能为过电离层EMPs传播时延矫正奠定基础,还可为区域电离层研究提供低轨道观测数据.Key to the timing and positioning of ElectroMagnetic Pulses(EMPs)using the multi-star time-of-arrival method is the precise derivation of propagation parameters and the elimination of ionospheric dispersion-induced delay.Traditional methods for deriving these parameters have several drawbacks,such as poor interference resistance,sensitivity to initial values,and an inability to extract radio wave birefringence signals.To address these issues,we introduce a novel approach for determining the propagation parameters of trans-ionospheric EMPs.This method not only calculates the beat frequency and Slant Total Electron Content(STEC)but also ascertains the signal′s absolute time of arrival after delay correction.Our spaceborne Wideband Electromagnetic Pulse Detector(WEMPD),orbiting at an altitude of 500 km with an inclination of 97.5°,has detected a total of 478 signals emitted from an electromagnetic pulse pulser.Comparative analysis with existing data reveals that when the STEC exceeds 10 TECU,the WEMPD-derived beat frequency is largely in agreement with predictions from the fixed-height geomagnetic field model,with an average relative error of 16.81%.The WEMPD-derived Vertical Total Electron Content(VTEC)aligns with International Reference Ionosphere predictions,with an average discrepancy of 2.35 TECU.The VTEC data obtained from WEMPD demonstrates an equivalent capacity to characterize the time-varying ionosphere as the Global Ionosphere Map published by the Chinese Academy of Sciences,with a consistent difference of approximately 10 TECU throughout the year.The significance of the higher-order effects in the WEMPD-derived STEC varies with the time of day,being approximately three times higher in the morning compared to the evening.After correcting for these higher-order effects,the timing accuracy of WEMPD has improved to 2.34μs,which is about a 20%enhancement over the pre-correction accuracy.These findings not only lay the groundwork for correcting the propagation delay of trans-ionospheric EMPs but also contr

关 键 词：宽带电磁脉冲探测器 电磁脉冲模拟器 电离层 倾斜电子总含量 

分 类 号：P352[天文地球—空间物理学]