Author(s): |
Youtian Niu, College of Physics and Information Engineering, Henan Normal University,Xinxiang 453007,China ; Henan Key Laboratory of Photovoltaic Materials,Xinxiang 453007,China Fangyu Wang, College of Physics and Information Engineering, Henan Normal University,Xinxiang 453007,China ; Henan Key Laboratory of Photovoltaic Materials,Xinxiang 453007,China Zhongyuan Zhang, College of Physics and Information Engineering, Henan Normal University,Xinxiang 453007,China ; Henan Key Laboratory of Photovoltaic Materials,Xinxiang 453007,China Xiaonian He, College of Physics and Information Engineering, Henan Normal University,Xinxiang 453007,China ; Henan Key Laboratory of Photovoltaic Materials,Xinxiang 453007,China Ningning Li, College of Physics and Information Engineering, Henan Normal University,Xinxiang 453007,China ; Henan Key Laboratory of Photovoltaic Materials,Xinxiang 453007,China |
Abstract: |
This paper analyzed the effect of the July 14,2000 extra-large solar flare burst on very low frequency( VLF) signal propagation at three paths from the west substation,master station and east substation of the Alpha VLF navigation system to the receive site in Xinxiang. This X5.7-class solar flare had caused the sudden phase anomalies(SPA) event on VLF signal phase. The VLF phase maximum measurement over the three 11.9kHz VLF signal propagation paths is about 62.5 cent cycles(cec), 30cec and 20cec respectively. According to the calculation results of the wave guide mode theory, the phase velocity maximum changed value of the three paths is approximately 7.4827×105m/s, 7.0895×105m/s and 6.1213×105m/s. The lower ionosphere effective reflection height fell about 14.5km, 13.8km and 11.9km respectively.
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