超低频极低频近区场研究

This project will demonstrate on the study of the near-field radiated by loop antenna and line antenna in SLF/ELF ranges, which serve for the underground resource dectection and the target monotoring under the sea-surface. It is noted that the SLF range is from 30 to 300 Hz, while the ELF range is below 30 Hz. This project deals with the quasi-static-field solution, approximated solution, and the exact solution under certain conditions for the near-field components radiated by a SLF/ELF radiated dipole in different region, which include the half-spaces, layered region, and Earth-ionosphere waveguide. In particular, the main research contents are included as follows: the study on the quasi-static-field in near zone of a SLF/ELF dipole source in the half-spaces or stratified media; the study on the numerical solution of the near-field of a SLF/ELF dipole source in the half-spaces or stratified media by using the speed-up numerical convergence algorithm; the study on the exact and approximated solutions on the time-domain field and frequency-domain field in the half-spaces; the study on the mode conversion actions of SLF/ELF waves by the inhomogeneous Earth-ionosphere waveguide; the study on the effects of the SLF/ELF near-field by anisotropic ionosphere; and the experimental study on the SLF/ELF near-field.

本项目针对地下资源探测和水下目标监测所牵涉到的超低频(SLF: 30～300Hz) 和极低频(ELF: 30Hz以下)频段环天线和线天线激励的近区场为研究对象。通过理论分析与数值仿真研究SLF/ELF辐射源在半空间、分层地层、地–电离层波导等区域激励的近区场的准静态解、近似解和半解析半数值解，以及某些特殊情况下的严格解。主要研究内容包括：研究半空间或分层媒质中SLF/ELF偶极子源激励的近区准静态解析解；利用加速收敛算法，求解SLF/ELF偶极子在半空间或分层媒质中激励的场分量近区场的数值解；研究半空间中磁偶极子激励的SLF/ELF近区场分量的频域和时域严格解和近似解；研究非均匀“地–电离层波导”引起的SLF/ELF波的模转换效应；研究电离层各向异性特性对SLF/ELF近区场的影响；开展SLF/ELF近区场测量实验研究。

本项目针对地下资源探测和水下目标监测所牵涉到的超低频（SLF：30~300Hz）和极低频（ELF：30Hz以下）频段环天线和线天线激励的近区场为研究对象。通过理论分析和数值仿真研究SLF/ELF辐射源在半空间、分层地层、地-电离层波导等区域激励的近区场的准静态解、近似解和半解析半数值解，以及某些特殊情况下的严格解。主要研究内容包括：研究半空间或分层媒质中SLF/ELF偶极子源激励的近区准静态解析解；利用加速收敛算法，求解SLF/ELF偶极子在半空间或分层媒质激励的场分量近区场的数值解；研究半空间磁偶极子激励的SLF/ELF近区场分量的频域和时域严格解和近似解；研究非均匀“地-电离层波导”引起的SLF/ELF的模转换效应；研究电离层各向异性特性对SLF/ELF近区场的影响；开展SLF/ELF近区场测量实验研究。