scholarly journals Analysis of GNSS Data Using Precise Point Positioning Technique for the Determination of Permanent Station in Romania

2015 ◽  
Vol 11 (3) ◽  
pp. 31-37
Author(s):  
Sorin Nistor ◽  
Aurelian Stelian Buda
Keyword(s):  
Precise Point Positioning ◽  
Neutral Atmosphere ◽  
International Gnss Service ◽  
Precise Orbit ◽  
Station Coordinates ◽  
Other Information ◽  
Point Positioning ◽  
Gnss Data ◽  
Permanent Station

Abstract To obtain the coordinates by means of precise point positioning (PPP) technique we need to use the undifferenced GPS pseudocode and carrier phase observations but to obtain the “precise” positioning we need precise orbit and clock data too. This products and other information for obtaining the results by using PPP technique on a centimeter level accuracy can be downloaded from different locations, but the most reliable satellite ephemerides and clock correction are available from International GNSS Service (IGS). In the PPP analysis we determined the parameters such as the receiver clock error, ionospheric delays code biases, code multipath and the total neutral atmosphere delay of the observations. For the determination of the permanent station coordinates, using the PPP technique, we used precise orbit and clock solutions to enable absolute positioning of a single receiver. In this article we present the results obtained by using the PPP technique on the permanent station Oradea, from which we can conclude that the PPP technique can be used for different GNSS application.

Improving PPP static and cinematic positioning by combining GPS and Galileo data.

2020 ◽  
Author(s):  
Felix Perosanz ◽  
Georgia Katsigianni ◽  
Sylvain Loyer ◽  
Mini Gupta ◽  
Alvaro Santamaria ◽  
...  
Keyword(s):  
Ambiguity Resolution ◽  
Precise Point Positioning ◽  
Pilot Project ◽  
Individual Performance ◽  
Differential Approach ◽  
Precise Orbit ◽  
Estimated Parameters ◽  
Station Coordinates ◽  
Point Positioning

<p><span><span>The Precise Point Positioning (PPP) technique using the GPS has become a popular alternative to the differential approach. Thanks to the MGEX pilot project of the IGS, precise orbit and clock products from other constellations like Galileo, Beidou, GLONASS are today available. This presentation focusses on GPS and Galileo systems and compares their individual performance to a combined processing. </span></span></p><p><span><span>Resolving GNSS phase observations biases to their correct integer values significantly improves the precision and the accuracy of the estimated parameters. However, PPP with ambiguity resolution (PPP-AR) requires to deal with “hardware” biases at the satellite and receiver level. Nevertheless, several Analysis Centers within the IGS community are providing these biases. Using the orbit, clock and bias products of the GPS and Galileo constellations provided by the CNES-CLS group, we were able to compare PPP and PPP-AR station coordinates repeatability from a network of around 50 stations during 6 months. For both static and cinematic solutions, the hybridized solution significantly exceeds both individual ones.</span></span></p><p><span><span> </span></span></p><p> </p>

scholarly journals Performance Analysis of Static Precise Point Positioning Using Open-Source GAMP

2020 ◽  
Vol 55 (2) ◽  
pp. 41-60
Author(s):  
Jabir Shabbir Malik
Keyword(s):  
Performance Analysis ◽  
Open Source ◽  
Observational Data ◽  
Precise Point Positioning ◽  
Three Dimensional ◽  
Satellite System ◽  
International Gnss Service ◽  
Positioning Accuracy ◽  
Position Accuracy ◽  
Point Positioning

AbstractIn addition to Global Positioning System (GPS) constellation, the number of Global Navigation Satellite System (GLONASS) satellites is increasing; it is now possible to evaluate and analyze the position accuracy with both the GPS and GLONASS constellation. In this article, statistical analysis of static precise point positioning (PPP) using GPS-only, GLONASS-only, and combined GPS/GLONASS modes is evaluated. Observational data of 10 whole days from 10 International GNSS Service (IGS) stations are used for analysis. Position accuracy in east, north, up components, and carrier phase/code residuals is analyzed. Multi-GNSS PPP open-source package is used for the PPP performance analysis. The analysis also provides the GNSS researchers the understanding of the observational data processing algorithm. Calculation statistics reveal that standard deviation (STD) of horizontal component is 3.83, 13.80, and 3.33 cm for GPS-only, GLONASS-only, and combined GPS/GLONASS PPP solutions, respectively. Combined GPS/GLONASS PPP achieves better positioning accuracy in horizontal and three-dimensional (3D) accuracy compared with GPS-only and GLONASS-only PPP solutions. The results of the calculation show that combined GPS/GLONASS PPP improves, on an average, horizontal accuracy by 12.11% and 60.33% and 3D positioning accuracy by 10.39% and 66.78% compared with GPS-only and GLONASS-only solutions, respectively. In addition, the results also demonstrate that GPS-only solutions show an improvement of 54.23% and 62.54% compared with GLONASS-only PPP mode in horizontal and 3D components, respectively. Moreover, residuals of GLONASS ionosphere-free code observations are larger than the GPS code residuals. However, phase residuals of GPS and GLONASS phase observations are of the same magnitude.

scholarly journals Determination of earthquake magnitude using GPS displacement waveforms from real-time precise point positioning

2013 ◽  
Vol 196 (1) ◽  
pp. 461-472 ◽  
Author(s):  
Rongxin Fang ◽  
Chuang Shi ◽  
Weiwei Song ◽  
Guangxing Wang ◽  
Jingnan Liu
Keyword(s):  
Real Time ◽  
Precise Point Positioning ◽  
Earthquake Magnitude ◽  
Point Positioning

Precise Point Positioning Model Using Triple GNSS Constellations: GPS, Galileo and BeiDou

2016 ◽  
Vol 10 (4) ◽  
Author(s):  
Akram Afifi ◽  
Ahmed El-Rabbany
Keyword(s):  
Real Time ◽  
Urban Areas ◽  
Precise Point Positioning ◽  
Convergence Time ◽  
Dual Frequency ◽  
Post Processing ◽  
International Gnss Service ◽  
Time Service ◽  
System Bias ◽  
Point Positioning

AbstractThis paper introduces a comparison between dual-frequency precise point positioning (PPP) post-processing model, which combines the observations of three different GNSS constellations, namely GPS, Galileo, and BeiDou and real-time PPP model. A drawback of a single GNSS system such as GPS, however, is the availability of sufficient number of visible satellites in urban areas. Combining GNSS observations offers more visible satellites to users, which in turn is expected to enhance the satellite geometry and the overall positioning solution. However, combining several GNSS observables introduces additional biases, which require rigorous modelling, including the GNSS time offsets and hardware delays. In this paper, a GNSS post-processing PPPP model is developed using ionosphere-free linear combination. The additional biases of the GPS, Galileo, and BeiDou combination are accounted for through the introduction of a new unknown parameter, which is identified as the inter-system bias, in the PPP mathematical model. Natural Resources Canada’s GPSPace PPP software is modified to enable a combined GPS / Galileo / BeiDou PPP solution and to handle the newly inter-system bias. A total of four data sets at four IGS stations are processed to verify the developed PPP model. Precise satellite orbit and clock products from the IGS-MGEX network are used to correct of the GPS, Galileo and BeiDou measurements. For the real-time PPP model the corrections of the satellites orbit and clock are obtained through the international GNSS service (IGS) real-time service (RTS). GPS and Galileo Observations are used for the GNSS RTS-IGS PPP model as the RTS-IGS satellite products are not available for BeiDou satellites. This paper provides the GNSS RTS-IGS PPP model using different satellite clock corrections namely: IGS01, IGC01, IGS01, and IGS03. All PPP models results of convergence time and positioning precision are compared to the traditional GPS-only PPP model. It is shown that combining GPS, Galileo, and BeiDou observations in a PPP model reduces the convergence time by 25 % compared with the GPS-only PPP model.

scholarly journals REVISITING THE ROLE OF OBSERVATION SESSION DURATION ON PRECISE POINT POSITIONING ACCURACY USING GIPSY/OASIS II SOFTWARE

2016 ◽  
Vol 22 (3) ◽  
pp. 405-419 ◽  
Author(s):  
Adem G. Hayal ◽  
D. Ugur Sanli
Keyword(s):  
Precise Point Positioning ◽  
Accuracy Assessment ◽  
Relative Positioning ◽  
International Gnss Service ◽  
Session Duration ◽  
Previous Formulation ◽  
Single Station ◽  
Analysis Strategies ◽  
Point Positioning

The accuracy of GPS precise point positioning (PPP) was previously modelled as a function of the observing session duration T. The NASA, JPL's software GIPSY OASIS II (GOA-II) along with the legacy products was used to process the GPS data. The original accuracy model is not applicable anymore because JPL started releasing its products using new modelling and analysis strategies as of August 2007, and the legacy products are no longer available. The developments mainly comprise the new orbit and clock determination strategy, second order ionosphere modelling, and single station ambiguity resolution. Previously, the PPP accuracy was studied using v 4.0 of the GOA-II. The accuracy model showed coarser results compared to that of the relative positioning. Here, we processed the data of the International GNSS Service (IGS) stations to refine the accuracy of GOA-II PPP from version 6.3. Considering the above changes we refined the accuracy of PPP. First we modified the previous model used for the accuracy assessment. Then we tested out this model using straightforward polynomial and logarithmic models. The tests indicate the previous formulation still satisfactorily models the accuracy using refined coefficient values Sn = 7.8 mm , Se = 6.8 mm , Sv = 29.9 mm for T ≥ 2 h.

scholarly journals Analysis on the Potential Performance of GPS and Galileo Precise Point Positioning using Simulated Real-Time Products

2018 ◽  
Vol 72 (1) ◽  
pp. 19-33 ◽  
Author(s):  
Francesco Basile ◽  
Terry Moore ◽  
Chris Hill
Keyword(s):  
Real Time ◽  
Precise Point Positioning ◽  
Satellite System ◽  
Convergence Time ◽  
Alternative Methods ◽  
International Gnss Service ◽  
Binary Offset Carrier ◽  
Time Service ◽  
Point Positioning ◽  
The Impact

With the evolving Global Navigation Satellite System (GNSS) landscape, the International GNSS Service (IGS) has started the Multi-GNSS Experiment (MGEX) to produce precise products for new generation systems. Various analysis centres are working on the estimation of precise orbits, clocks and bias for Galileo, Beidou and Quasi-Zenith Satellite System (QZSS) satellites. However, at the moment these products can only be used for post-processing applications. Indeed, the IGS Real-Time service only broadcasts Global Positioning System (GPS) and Globalnaya Navigatsionnaya Sputnikovaya Sistema (GLONASS) corrections. In this research, a simulator of multi-GNSS observations and real-time precise products has been developed to analyse the performance of GPS-only, Galileo-only and GPS plus Galileo Precise Point Positioning (PPP). The error models in the simulated orbits and clocks were based on the difference between the GPS Real-Time and the Final products. Multiple scenarios were analysed, considering different signals combined in the Ionosphere Free linear combination. Results in a simulated open area environment show better performance of the Galileo-only case over the GPS-only case. Indeed, up 33% and 29% of improvement, respectively, in the accuracy level and convergence time can be observed when using the full Galileo constellation compared to GPS. The dual constellation case provides good improvements, in particular in the convergence time (47% faster than GPS). This paper will also consider the impact of different linear combinations of the Galileo signals, and the potential of the E5 Alternative Binary Offset Carrier (AltBOC) signal. Even though it is significantly more precise than E5a, the PPP performance obtained with the Galileo E1-E5a combination is either better or similar to the one with Galileo E1-E5. The reason for this inconsistency was found in the use of the ionosphere free combination with E1. Finally, alternative methods of ionosphere error mitigation are considered in order to ensure the best possible positioning performance from the Galileo E5 signal in multi-frequency PPP.

scholarly journals Evaluation of Inter-System Bias between BDS-2 and BDS-3 Satellites and Its Impact on Precise Point Positioning

2020 ◽  
Vol 12 (14) ◽  
pp. 2185 ◽  
Author(s):  
Wen Zhao ◽  
Hua Chen ◽  
Yang Gao ◽  
Weiping Jiang ◽  
Xuexi Liu
Keyword(s):  
Precise Point Positioning ◽  
Satellite System ◽  
Navigation Satellite ◽  
International Gnss Service ◽  
Beidou Navigation Satellite System ◽  
System Bias ◽  
Point Positioning ◽  
Kinematic Ppp ◽  
The Impact

The BeiDou navigation satellite system (BDS) currently has 41 satellites in orbits and will reach its full constellation following the launch of the last BDS satellite in June 2020 to provide navigation, positioning, and timing (PNT) services for global users. In this contribution, we investigate the characteristics of inter-system bias (ISB) between BDS-2 and BDS-3 and verify whether an additional ISB parameter should be introduced for the BDS-2 and BDS-3 precise point positioning (PPP). The results reveal that because of different clock references applied for BDS-2 and BDS-3 in the International GNSS Service (IGS) precise satellites clock products and the inconsistent code hardware delays of BDS-2 and BDS-3 for some receiver types, an ISB parameter needs to be introduced for BDS-2 and BDS-3 PPP. Further, the results show that the ISB can be regarded as a constant within a day, the value of which is closely related to the receiver type. The ISB values of the stations with the same receiver type are similar to each other, but a great difference may be presented for different receiver types, up to several meters. In addition, the impact of ISB on PPP has also been studied, which demonstrates that the performance of kinematic PPP could be improved when ISB is introduced.

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