The Influence of Solar Flare on Low Frequency Time-Code Timing Signal

Low frequency time-code timing signal is mainly composed of the mixture of sky wave and ground wave. As the distance increases, the propagated influence factors of the sky wave are also increased. What's more, the mutation of the ionosphere caused by the eruption of the solar flare will affect the propagation of the sky wave. So, it is possible to infer that the solar flare will affect the signal strength of the low frequency time-code timing signal. To verify the influence of solar flares on the low-frequency timing signal, the paper starts with the influence mechanism of ionosphere on radio signals, sets up the low frequency signal monitoring system, analyzes the influence of solar flare on low frequency signal, assesses the effect of space weather on low frequency signals in real time. Based on historical data and actual monitoring data, 4 typical solar flare events were selected to analyze the signal strength of low frequency timing signal during solar flare. From the result of observation experiment, we can see that the burst of solar flare above C7 level has significant influence on the signal strength of the low frequency continuous wave signal. In addition, the field strength response trend of the low frequency signal is also different, and they vary with the monitoring distance. What's more, the influence degree of the different level solar flare on the low frequency time-code timing signal is different. When the solar flare level is higher, the attenuation range of the signal strength value is larger, and the impact on the low frequency time-code timing signal is greater as well.