11:15 AM - 11:30 AM
[G05-2-04] Quality of GPS, GLONASS, Galileo and BeiDou real-time orbits and clocks
A constantly increasing number of satellites of Global Navigation Satellites Systems (GNSS) and their continuous modernization allow improving the positioning accuracy and enables performing the GNSS measurements in demanding environments. In order to take advantage of all GNSS and their frequencies it is necessary to get precise orbits and clocks also for new systems. To provide such products Multi-GNSS experiment (MGEX) has been established by the International GNSS Service (IGS). Products ensured by IGS may be used only in post-processing mode due to the latency of these products.
IGS Real-Time Service (RTS) was launched in April 2013 in order to pave the way for obtaining the position in real-time. Products provided currently by IGS-RTS are available only for GPS and GLONASS. Therefore, to enable real-time users to take advantage of all GNSS observations it is necessary to provide orbit and clock corrections for all available GNSS via streams. Centre National d'etudes Spatiales (CNES) is one of analysis centers that provides freely available corrections for all GNSS, including new systems.
The presented work evaluates the availability and quality of real-time corrections. The final products provided by the Center of Orbit Determination in Europe (CODE) and Satellite Laser Ranging (SLR) are used as a reference for the evaluation of real-time products. The 3D orbit RMS, when compared to CODE products, is 5, 10, 19, 18 and 37~cm for GPS, GLONASS, Galileo, BeiDou MEO and IGSO, respectively. The insufficient quality of BeiDou geostationary orbits that reaches above 1~m is inadequate for precise positioning applications. The conducted works are a background for further studies related to the real-time Multi-GNSS processing, e.g. using the proper system-specific weighing of observations in order to achieve reliable multi-GNSS solutions.
IGS Real-Time Service (RTS) was launched in April 2013 in order to pave the way for obtaining the position in real-time. Products provided currently by IGS-RTS are available only for GPS and GLONASS. Therefore, to enable real-time users to take advantage of all GNSS observations it is necessary to provide orbit and clock corrections for all available GNSS via streams. Centre National d'etudes Spatiales (CNES) is one of analysis centers that provides freely available corrections for all GNSS, including new systems.
The presented work evaluates the availability and quality of real-time corrections. The final products provided by the Center of Orbit Determination in Europe (CODE) and Satellite Laser Ranging (SLR) are used as a reference for the evaluation of real-time products. The 3D orbit RMS, when compared to CODE products, is 5, 10, 19, 18 and 37~cm for GPS, GLONASS, Galileo, BeiDou MEO and IGSO, respectively. The insufficient quality of BeiDou geostationary orbits that reaches above 1~m is inadequate for precise positioning applications. The conducted works are a background for further studies related to the real-time Multi-GNSS processing, e.g. using the proper system-specific weighing of observations in order to achieve reliable multi-GNSS solutions.