桂林地区TEC起伏与L波段闪烁强度的比较研究

Comparative study on TEC fluctuation and L-band fluctuation intensity in Guilin

无线电波穿过不规则体传播后,地面接收信号的振幅和相位出现快速随机起伏,即电离层闪烁.闪烁可能造成卫星导航和通信等技术系统的性能下降,严重时可能导致信号中断,因此,对不规则体和闪烁的研究一直是人们关注的焦点.前人研究表明,与电离层不规则体相伴随的总电子含量(TEC)的起伏与闪烁的出现相关.该文利用位于桂林的电离层闪烁接收台站的自主观测数据,分析了TEC起伏与振幅闪烁强度的相关性和定量关系.结果表明,量化TEC起伏的两个指数ROTI和σ_(tec)都与S_(4)指数存在显著正相关,这反映了大尺度和小尺度不规则体一般同时存在的特征;定量关系表明,对相同强度的不同闪烁事件,ROTI与S_(4)指数的比值变化范围较大,σ_(tec)与S_(4)指数的比值变化范围相对较小,σ_(tec)一定程度上优于ROTI对S_(4)指数的定量估计.

The radio wave propagating through irregularities can cause rapid random fluctuations in the amplitude and phase of the received signal on the ground,which is called the ionospheric scintillation.Scintillation may degrade the performance of satellite navigation,communication and other technical systems,causing signal interruption in some serious cases.Therefore,the study of irregularities and scintillations has always been the focus of attention.Previous studies have shown that the fluctuation of total electron content(TEC)accompanied with ionospheric irregularities is related to the occurrence of scintillations.Based on the observation data of ionospheric scintillation receiving station located in Guilin,analysis on the correlation and quantitative relationship between TEC fluctuation and amplitude scintillation intensity has been made.The results show that both ROTI index and σ_(tec) index,which quantify the fluctuation of TEC,have significant positive correlation with S_(4) index,which reflects the feature that large scale irregularities usually coexist with the small scale irregularities;the quantitative relationship shows that,for different scintillation events with the same intensity,the ratio of ROTI to S_(4) index varies in a larger range compared with the ratio of σ_(tec) index to S_(4) index,To some extent,σ_(tec) index reflects the quantitative estimation of scintillation intensity better than ROTI index.