甚低频在多模干涉区的场强起伏标准偏差估计  

Estimation of VLF amplitude standard deviation in multimode interference region

作　　者：张世田[1] 陈恩平[1] 王元新[1] 潘威炎[1] 张红旗[1] 

机构地区：[1]中国电波传播研究所,山东青岛266071

出　　处：《电波科学学报》2011年第2期286-290,共5页Chinese Journal of Radio Science

摘　　要：对于甚低频(VLF)电波而言,电离层随机不规则变化将影响传播路径上场强的稳定性,从而使得场强起伏在多模区特别是场强极小点附近较为明显。从VLF电波传播基理出发、研究分析了传播路径上电离层随机不规则变化对场强稳定性的影响,推导了多模干涉区、单模干涉区及场强极小点附近激励因子、哀减率和相速与场强起伏的关系,得出了传播路径上场强起伏标准偏差估计公式,并将此公式的理论计算结果与实测数据进行了对比。结果证明:此公式计算精度较高,能够自适应于多模干涉区、单模干涉区,此场强起伏标准偏差估计公式对VLF通信可靠性的研究具有重要意义。The ionospheric random irregular variety induces the amplitude fluctuation of very low frequency（VLF） wave, which is acute in the multimode interference region especially near the points where VLF field strength is minimum. Base on the standard deviation of the ionospheric reflect height, the fluctuation of attenuation rate and phase velocity for each mode are estimated with the theory of VLF wave propagation, then an estimation formulation of standard deviation for total filed is deduced. This formulation may be used both in the multi-mode and unimode regions, the calculation result of the formulation coincides well with the experiment datum. The formulation of standard deviation of amplitude fluctuation benefits the study about dependability of communications using VLF wave.

关 键 词：多模干涉区 标准偏差 可靠度 自相关函数 

分 类 号：TN011[电子电信—物理电子学]