Ionospheric TEC Research Based On Beidou Satellite Navigation System

The positioning of satellite navigation systems are affected by the atmosphere of its activities, especially in the atmosphere which has the greatest impact of the ionosphere on radio wave propagation. Thus as a propagation medium, the ionosphere resulting in different wavelengths of reflected radio waves in the ionosphere, refraction, scattering and absorption, affected the communications and broadcasting to a certain extent. So it has very important significance to monitor the activities of the ionosphere to improve satellite navigation user navigation and positioning accuracy.Recently years, as the representative of GPS GNSS observation technology development, so that the use of GNSS observation data in real-time accurate extraction and determination of total electron content(TEC) of the ionosphere, and then the real-time monitoring of ionospheric TEC change activities as possible. Domestic and foreign scholars have used the GPS data observed in the ionosphere carried out extensive research, the most authoritative international ionospheric products are provided by the International GNSS Service Organizations ionosphere group, IGS ionosphere group aims to provide high-precision global ionospheric FIG and GNSS satellites and various stations DCB parameters, studies show that the use of GNSS observation data solver largest error source of the total electron content of the ionosphere and the satellite receiver hardware is DCB delay. The use of Beidou navigation system to monitor observational data ionospheric research work is relatively small, unlike the American GPS, Beidou satellite system, although in recent years, China has been the rapid development of the use of Beidou satellite data solver total electron content of the ionosphere and satellites and DCB hardware receiver delay estimation precision is an urgent need to address the problem.Firstly, the use of dual-frequency observations of single BDS, using the least squares method solver the Differential code biases of satellite and receiver, compare the result with the geodesic announced DCB products, and GPS system DCB products to further verification. Meanwhile, in order to make up for problems with the distribution of ionospheric modeling BDS satellite constellation to provide uniform distribution of observational data, this paper combined with Chinese regional Beidou and GPS satellite data, using spherical harmonic model to get DCB product, and compare its results with geodesic announced DCB products and IGS released DCB products, and then obtain DCB product accuracy and stability evaluation. Meanwhile, the paper also uses a single Compass data, single GPS data and dual-system data to calculate the ionosphere TEC, analysis and compare the result.GPS ionospheric TEC calculation accuracy of better than BDS, while the dual-system data calculation ionospheric TEC accuracy better than the results of single GPS and single BDS calculated.