Ionospheric TEC prediction and analysis based on phase space reconstruction

It is very important for the ionospheric total electron content (TEC) to be predicted in the earth-based or space-based systems. Since the ionospheric TEC is affected by many factors and there are high complexity and non-linearity between every factor and TEC value, this paper will use Chaos, one of the nonlinear theories, to analyze the ionospheric TEC time series. From the ionospheric product of CODE, 1442 vertical total electron content (VTEC) values have been extracted, located in E115 (longitude) and N40 (latitude), with 2 hours intervals. By calculation of Wolf method, the plus maximum Lyapunov exponent of the VTEC time series (0.0230) was acquired, justifying that the VTEC time series have chaotic characters and it is appropriate for the application of the chaotic theory. Based on the calculation of delay time and the embedding dimension number, the reconstruction of phase space has been realized. Besides, the multi-step prediction and testing of the VTEC time series were performed by means of adding-weight one-rank local-region method.