300 kHz以下频段电波传播研究进展  

Progress in radio wave propagation below 300 kHz

作　　者：李清亮[1] 张世田[1] 刘凯[1] 彭怀云 LI Qingliang;ZHANG Shitian;LIU Kai;PENG Huaiyun(National Key Lab of Electromagnetic Environment,China Research Institute of Radiowave Propagation,Qingdao 266107,China)

机构地区：[1]中国电波传播研究所电波环境特性及模化技术重点实验室,青岛266107

出　　处：《电波科学学报》2023年第4期574-590,共17页Chinese Journal of Radio Science

基　　金：国家自然科学基金(62271457)。

摘　　要：300 kHz以下频段是深海、深地、深空探测以及远距离通信导航等无线电系统的重要频谱资源,其电波传播特性持续受到人们的关注并得到了快速发展.本文主要介绍中国电波传播研究所和国内相关合作团队在此方面的研究进展.针对对地基导航授时系统有重要影响的附加二次时延(additional secondary phasefactor,ASF),发展了理论与实验测量相结合满足工程需要的ASF修正模型.针对水中目标探测和电磁辐射问题,发展了跨海面(床)电波传播时域有限差分(finite-difference time-domain,FDTD)计算方法,相对于传统的Sommerfeld积分方程,解决复杂问题的能力大幅提升.针对空间环境探测与应用涉及的星-地链路问题,分别从全波解、积分方程和FDTD三种方法出发,解决了地基或天基VLF辐射源跨介质传播计算,建立了各向异性电离层中线天线分析理论方法.针对VLF地-电离层波导远距离传播问题,在传统波导模理论的基础上,发展了有限元法(finite element method,FEM)和测算融合方法,前者为昼夜过渡区波模转换提供了解决途径,后者为传播链路高精度预测奠定了基础.最后,从计算方法和计算中所用物理参数两方面,提出了研究展望.The frequency band below 300 kHz is an important spectrum resource for radio systems such as deepsea,deep-earth,deep-space exploration,long-distance communication,navigation etc.Their radio wave propagation characteristics continue to attract attention and development.This paper mainly introduced the research progress of China Research Institute of Radiowave Propagation and relevant domestic cooperative teams in this field.In view of additional secondary phase factor(ASF),which has important influence on the ground-based navigation timing system,a modified ASF model which combines theory with experimental measurement and meets engineering requirements is developed.In order to solve the problem of underwater target detection and electromagnetic radiation,a finitedifference time-domain(FDTD)calculation method for radio wave propagation across the sea surface(bed)is developed.Compared with the traditional integral equation,this method has greatly improved the ability of solving complex problems.Aiming at the satellite-Earth link problem involved in space environment detection and application,based on the three methods of total method,integral equation and FDTD,the problem of transdielectric propagation calculation of ground-based or space-based very low frequency(VLF)radiation source is solved,and the theoretical method of analyzing the anisotropic ionospheric midline antenna is established.In order to solve the long-distance propagation problem of VLF ground-ionospheric waveguide,finite element method(FEM)and calculation fusion method are developed on the basis of traditional waveguide mode theory.The former provides a solution for the wave mode conversion in the diurnal transition zone,and the latter lays a foundation for the high-precision prediction of propagation link.Finally,from the calculation method and the physical parameters used in the calculation process,the research prospect is put forward.

关 键 词：300 kHz以下频段 电波传播 ASF 地-电离层波导 跨介质传播 电离层中线天线 

分 类 号：TN959.72[电子电信—信号与信息处理]