Latest Data
Introduction

The CAS Forecast 1 Day Ionospheric product provides global vertical ionospheric TEC information predicted one day in advance at a temporal resolution of 1 hour, a spatial resolution of 2.5° zonal and 5° longitude, and a thin ionospheric height of 450km in TECu (1 TECu corresponds to a 16.2 cm pseudo-distance delay on the L1 frequency). The prediction of ionospheric products is obtained based on the maximum posteriori estimation theory. On the basis of CAS fast ionospheric products, the change period of spherical harmonic coefficients of each order is extracted by power spectrum analysis, and the main period term of spherical harmonic coefficients is included in the trend function for fitting. Then, the wide stationary signals which are not fitted with the trend term are predicted based on the maximum posteriori estimation method. 1, 2 and 5 day global ionospheric TEC forecasts are achieved.

Product Standard
Specification Description
Provider Chinese Academy of Sciences(CAS)
Data Input Fast GIM of CAS
Data Processing Global ionospheric prediction method based on maximum posteriori prediction theory
Coverage Area -90°N – 90°N, 180°W – 180°E
Thin Layer Height 450Km
Spatial Resolution 2.5° Lat x 5° Lon
Temporal Resolution 1 hour
Data Format IONEX
Data Download ftp://ftp.gipp.org.cn/product/ionex/
Reference Li et al. 2014