电波科学学报2025，Vol.40Issue(4)：611-627,17.DOI:10.12265/j.cjors.2025189
VHF超视距多模耦合传播机理研究
Study on the multi-mode coupling propagation mechanism of VHF BLoS Links
摘要
Abstract
Very high frequency(VHF,30-300 MHz)beyond-line-of-sight(BLoS)radio propagation primarily involves three medium-based modes:ionospheric volume or surface scattering(including meteor trails),tropospheric volume or surface scattering,and terrain diffraction.Current research predominantly focuses on individual propagation modes independently,addressing propagation calculations,channel modeling,and link analysis,In fact,irregular structures with diverse refractivity gradients exist in both the ionosphere and troposphere,enabling five propagation mechanisms for BLoS links:refraction,reflection,scattering,diffraction,and continuous medium propagation.Simultaneously,spatiotemporal random evolution of refractivity gradient structures in ionospheric and tropospheric irregularities leads to coupling between intra-layer and inter-layer propagation modes,collectively influencing actual transmission links.Conventional calculation methods based on single-medium propagation modes are inadequate for guiding engineering computation and analysis effectively.This paper begins with the fundamental properties of refractivity gradient structures in the ionosphere and troposphere,analyzes the applicability of the five propagation mechanisms,and proposes a multi-mode coupled propagation calculation method for VHF BLoS links.For observed VHF BLoS phenomena inadequately explained by single-medium,single-mode,or single-effect models,a link loss calculation method based on refractivity gradient structures elucidates the mechanism of multi-mode coupled propagation,and has preliminarily demonstrated practical values.关键词
超短波/超视距传播/对流层-电离层-地形地物/多模耦合/链路分析Key words
very high frequency(VHF)/beyond-line-of-sight(BLoS)propagation/troposphere-ionosphere-terrain features/multi-mode coupling/link analysis分类
信息技术与安全科学引用本文复制引用
李国军,弓树宏,于全..VHF超视距多模耦合传播机理研究[J].电波科学学报,2025,40(4):611-627,17.基金项目
国家自然科学基金重点项目(U22A2006) （U22A2006）
重庆市自然科学基金项目(CSTB2023NSCQ-LZX0082) （CSTB2023NSCQ-LZX0082）
科技委基础加强重点项目(2022-173-SD-1) （2022-173-SD-1）
国家重点研发计划"社会治理与智慧社会科技支撑(平安中国)"重点专项(2022YFC3301300) （平安中国）
