Abstract:Based on GPS observations from CMONOC, the RIM over China is derived precisely. We introduce a new method of singular spectrum analysis(SSA) to estimate the prediction models of TEC extracted from RIM. A suitable length of original TEC time series of 27 days is selected. By the w-correlation, the RC and window size of prediction model can be also determined. It is found that when the size of window is set as 1/3 of original series, the iteration of the first 5 RC decomposed by SSA has the best effects. The TEC data at center grid point of RIM from 1 to 27 d, 101 to 127 d, 201 to 227 d, 301 to 327 d are extracted respectively, to predict TEC for 7 days by SSA method. Meanwhile, the ARMA prediction model is also found and the models are compared. The results show that, compared with the ARMA model, the relative accuracy of SSA model is improved 10% for 7 days, with better long-prediction and anti-magnetic abilities. Furthermore, the TEC data of 2911 points are predicted by both methods. It is found that the RMSE gradually rose along with the decline of latitude, while the relative accuracy of grids over mid-latitude is slightly higher than other regions. However, regardless of the evaluation index, the SSA prediction model is superior to ARMA model.