Space State Representation Product Evaluation in Satellite Position and Receiver Position Domain

Abstract

<jats:p>In Global Navigation Satellite Systems (GNSS) positioning, important terms in error budget are satellite orbits and satellite clocks correction errors. International services are developing and providing models and correction to minimize the influence of these errors both in post-processing and real-time applications. The International GNSS Service (IGS) Real-Time Service (RTS) provides real-time orbits and clock corrections for the broadcast ephemeris. Real-time products provided by IGS are generated by different analysis centres using different algorithms. In this paper, four RTS products—IGC01, CLK01, CLK50, and CLK90—were evaluated and analysed. To evaluate State Space Representation (SSR) products’ GPS satellites, the analyses were made in three variants. In the first approach, geocentric real-time Satellite Vehicle (SV) coordinates and clock corrections were calculated. The obtained results were compared with the final IGS, ESA, GFZ, and GRG ephemerides. The second approach was to use the corrected satellite positions and clock corrections to determine the Precise Point Position (PPP) of the receiver. In the third analysis, the impact of SSR corrections on receiver Single Point Position (SPP) was evaluated. The first part of the research showed that accuracy of the satellite position is better than 10 cm (average 3 to 5 cm), while in the case of clock corrections, mean residuals range from 2 cm to 17 cm. It should be noted that the errors of the satellites positions obtained from one stream differ depending on the reference data used. This shows the need for an evaluation of correction streams in the domain of the receiver position. In the case of PPP in a kinematic mode, the tests allowed to determine the impact that the use of different streams has on the final positioning results. These studies showed differences between specific streams, which could not be seen in the first study. The best results (3D RMS at 0.13 m level) were obtained for the CLK90 stream, while for IGC01, the results were three times worse. The SPP tests clearly indicate that regardless of the selected SSR stream, one can see a significant improvement in positioning accuracy as compared to positioning results using only broadcast ephemeris.</jats:p>

Performance of Multi-GNSS Real-Time UTC(NTSC) Time and Frequency Transfer Service Using Carrier Phase Observations

“…The multi-GNSS products were distributed through the internet, based on the SSR format. The SSR correction, combined with the corresponding individual GNSS broadcast ephemeris, was used to recover the precise satellite orbit and clock, which were then transmitted to the GNSS time transfer software (PTTSol) [32,33]. The real-time GNSS data of at least of two stations with time and frequency references were also collected using NTRIP caster software.…”

Research on BeiDou Satellite Positioning Algorithm Based on GPRS Technology

“…When the satellite signal passes through the ionosphere, troposphere, and other media, they are refracted and reflected and errors are produced. e existence of these errors greatly reduces the accuracy of BeiDou positioning [3]. Eliminating or weakening the influence of various errors in BeiDou positioning is a very important task for high-precision real-time dynamic positioning systems [3,4].…”

“…e existence of these errors greatly reduces the accuracy of BeiDou positioning [3]. Eliminating or weakening the influence of various errors in BeiDou positioning is a very important task for high-precision real-time dynamic positioning systems [3,4].…”