Abstract:By testing the length of time series, the influence of geomagnetic index on the exclusion of geomagnetic activity and geomagnetic activity is analyzed. For the periodic variation of the TEC value of the ionosphere and its inhomogeneous distribution with latitude, we use the seasonal time series model, SARIMA and the Holt-Winters exponential smoothing model. 48 regions of different latitudes of the northern hemisphere are predicted using the TEC grid data provided by the IGS Center, and the daily mean relative accuracy and root mean square error are defined to assess forecast accuracy. The results show that all three models can reflect the cyclical changes of ionospheric TEC values, but the root mean square error decreases with the latitude and shows an overall trend of growth; at 25° and 55° north latitude it shows a maximum value, while at 45° N, it shows a minimum value.
CHEN Yutian,LIU Lilong,LIU Zhongliu et al. Analysis of the Influence of Latitude Factors on Seasonal Time Series TEC Short-Term Forecast Model[J]. jgg, 2018, 38(6): 581-586.