Monitoring Temporal and Spatial Variations of Ionospheric TEC Using GPS Measurements

The study of the ionospheric temporal and spatial variations has important value for satellite navigation, aerospace and communications. In this paper, the GPS dualfrequency observation data provided by the IGS station are used to estimate the hardware delay of the GPS system by using the regional ionosphere model to calculate the total electron content of the absolute ionosphere. On the time scale, we select the data in 2012, 2015 and 2017 of COR1 station for time change analysis. The total ionospheric electron content shows diurnal, monthly and seasonal variations in time. In terms of space, four IGS stations, CRO1, BRMU, UNBJ, and QIKI, with small differences in longitude and uniform distribution in the latitude direction, are selected for analysis. The results show that there is an obvious unimodal effect in latitude direction, and the total electron content of the ionosphere shows a decreasing trend with increasing latitude.