摘要
利用位于挪威斯瓦尔巴岛黄河站的三频信标接收系统的VHF波段信号强度数据,对2011年10月至2015年10月期间极区电离层VHF电波闪烁的强度、功率谱、闪烁发生次数的季节和地方时特性以及信号强度的概率密度进行了统计分析。结果表明,谱指数n与S4指数之间存在明显正相关,且随着n的增加,S4指数趋向饱和。强地磁活动对S4>1. 5的强闪烁有明显抑制作用,对S4>0. 4的闪烁也表现出一定程度的抑制作用。闪烁发生率春季最高,秋季最低,但季节依赖性不明显;闪烁的地方时依赖性主要表现为夜间发生率较低,午后发生率最高。闪烁信号强度的概率密度在S4<0. 6时更接近Nakagami-m分布,在S4>0. 6时更接近Rayleigh分布。
Statistical features of the intensity,power spectrum,seasonal and local-time characteristics of the number of scintillation occurrences,and probability density of signal intensity of polar ionospheric VHF scintillations were investigated based on VHF signal intensity data from the triband beacon receiving system at Yellow River station,Svalbard island,Norway,between October 2011 and October 2015.The results show that there is a clear positive correlation between the spectrum index n and the S4 index.Besides,the S4 index tends to saturation with the increasing n.Strong geomagnetic activities show obvious restraint effect on the strong scintillation with S4>1.5,and restraint effect to some extent on the scintillation with S4>0.4.In general,it shows the highest scintillation occurrence in spring and the lowest one in autumn,but the seasonal dependence is not evident;the local time dependence of scintillation is mainly manifested by the lower incidence at night and the highest incidence in the afternoon.The probability density of the scintillation signal intensity is closer to the Nakagami-m distribution when S4<0.6,and closer to the Rayleigh distribution when S4>0.6.
作者
姜珂
徐良
JIANG Ke;XU Liang(School of Electronic Information,Wuhan University,Wuhan 430072,Hubei,China)
出处
《武汉大学学报（理学版）》
CAS
CSCD
北大核心
2019年第5期510-518,共9页
Journal of Wuhan University:Natural Science Edition
基金
海洋公益性行业科研专项项目(201005017)
关键词
极区电离层闪烁
S4指数
闪烁出现率
地磁活动
概率密度
polar ionospheric scintillation
S4 index
scintillation occurrence
geomagnetic activities
probability density
