Preliminary studies on ionospheric forecasting in China and its surrounding area

The ionospheric sounding in China has a long history and has a well spread network, which is still keeping routine operation. The autocorrelation method is adopted for the short-term forecasting of ionospheric characteristics. The performances of the forecasts at Chongqing have been examined for different combination of parameters and algorithms by estimating the prediction errors. Preliminary results show that for predictions of more than 10 h ahead the “at once” method with f0F2 is preferable. For predictions of less than 10 h ahead the “iterations” method with RDF=(f0F2-f0F2¯)/f0F2¯ is the best. A corrected method of the International Reference Ionosphere used in China region (the CRI model) is described in this paper. By introducing an effective ionospheric index Ice into the CRI model the regional forecasting could be realized.