Calculation of the Ephemeris and Clock Corrections of GLONASS and GPS Navigation Space Vehicles in Ultra-Rapid Regime on the Basis of Measurement Data

An algorithm and program for calculation in ultra-rapid regime of the ephemeris and time information of GLONASS and GPS navigation space vehicles are developed. The results presented here were obtained at the Main Metrological Center of the State Time and Frequency Service and Determination of the Parameters of the Earth’s Rotation at the All-Russia Research Institute of Physicotechnical and Radio Measurements (VNIIFTRI). Calculations of the ephemeris and time information are performed on the basis of the data of code and phase measurements at two carrier frequencies. The measurement data are presented in the form of hourly RINEX files of observations and files of navigation messages from tracking stations in the network of the IGS international service of global navigation satellite systems (International GNSS Service). Results of test calculations of the ephemeris and clock corrections of GLONASS and GPS navigation satellites in ultra-rapid regime are presented. An analysis of the precision of the results as compared to a posteriori (final) data from other data processing and analysis centers is presented.