Performance assessment of multi-GNSS real-time PPP over Iran

Abdi, Naser; Ardalan, Alireza A.; Karimi, Roohollah; Rezvani, Mohammad-Hadi

doi:10.1016/j.asr.2017.03.024

Cited by 34 publications

(18 citation statements)

References 32 publications

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“…The single-day frequency stability analysis of the TDOA sequence shows that the single day stability index of the TDOA sequence obtained by the fusion PPP is about the magnitude of 10 −14 , and the average frequency stability is 3.0 × 10 −14 . This shows that it is feasible to use the fusion PPP method to monitor the time difference of the system from the precision [13].…”

Section: Short Term Stability Of Fusion Ppp Pseudo-time Difference Rementioning

confidence: 92%

Research on time difference detection algorithm based on combination of GNSS and PPP

Yang

Zhang

Liu

et al. 2019

J Wireless Com Network

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With the gradual increase in the number of GNSS systems and the improvement of functions, in addition to the singlesystem navigation and timing service, the integrated navigation and positioning service among multiple systems can provide users with more accurate and stable positioning results, arousing more attention from the workers in GNSS field. Compatibility and interoperability among different systems has become a trend in the development of GNSS. Compatibility and interoperability between systems require a uniform time scale. Therefore, the measurement and forecasting of time deviations in GNSS systems is particularly important. This paper first studies the multi-system fusion location model and proposes an adaptive GNSS fusion PPP algorithm based on parameter equivalent reduction. Then, the method of fusion PPP is used to monitor the time difference of GNSS. Finally, the effectiveness of the improved algorithm and time difference monitoring method is verified by practical examples.

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Section: Short Term Stability Of Fusion Ppp Pseudo-time Difference Rementioning

confidence: 92%

Research on time difference detection algorithm based on combination of GNSS and PPP

Yang

Zhang

Liu

et al. 2019

J Wireless Com Network

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“…European Space Agency's Space Operations Centre in Darmstadt, Germany (ESA/ESOC), Deutsches GeoForschungs Zentrum (GFZ), GMV Aerospace and Defense (GMV), Natural Resources Canada (NRCAN), and Wuhan University WUHAN. Real-time PPP was assessed for static and kinematic applications using GPS only [13], GPS + GLONASS [14], GPS + GLONASS + BeiDou [15], and GPS + GLONASS + Galileo + BeiDou [10] [16] [17]. Galileo-only PPP and its contribution to GPS PPP were investigated using the final precise ephemeris for both static and post-processed kinematic modes [18].…”

Section: Centre National D'etudes Spatiales (Cnes) German Aerospace mentioning

confidence: 99%

“…The NAVCAST real-time broadcast ephemeris, orbit and clock corrections were saved using the BNC software. The detailed strategy of PPP in BNC used in this research is the same as in [15] and the positioning errors are modeled as a random walk process with spectral densities zero in the horizontal and vertical directions, as the processing mode is static. Figure 1.…”

Section: Static Test Data Collectionmentioning

confidence: 99%

“…The reference GNSS station was TORO station, which is one of Cansel's GNSS permanent network (CAN-NET) in the Toronto area with a baseline of about 16 km. The detailed strategy of PPP in BNC used in this research is the same as in [15] and the positioning errors are modeled as a random walk process with spectral densities 100 m 2 /s in the horizontal and vertical directions. Positioning .…”

Section: Kinematic Testmentioning

confidence: 99%

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Real-Time GPS/Galileo Precise Point Positioning Using NAVCAST Real-Time Corrections

Elmezayen¹,

El-Rabbany²

2019

POS

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Real-time precise point positioning (PPP) is possible through the use of real-time precise satellite orbit and clock corrections, which are available through a number of organizations including the International GNSS Service (IGS) real-time service (IGS-RTS). Unfortunately, IGS-RTS is only available for the GPS and GLONASS constellations. In 2018, a new real-time service, NAVCAST, which provides real-time precise orbit and clock corrections for the GPS and Galileo constellations, was launched. In this research, the potential performance of real-time PPP which makes use of NAVCAST real-time corrections is analyzed using various static and kinematic datasets. In the static dataset, 24 hours of observations from eight IGS stations in Canada over three different days were utilized. The static results show that the contribution of Galileo satellites can improve the positioning accuracy, with 30%, 34%, and 31% in east, north, and up directions compared to the GPS-only counterparts. In addition, centimeter-level positioning accuracy in the horizontal direction and decimeter-level positioning accuracy in the vertical direction can be achieved by adding Galileo observations. In the kinematic dataset, a real vehicular test was conducted in urban and suburban combined areas. The real-time kinematic GPS/Galileo PPP solutions demonstrate an improvement of about 53%, 45%, and 70% in east, north, and up directions compared to the GPS-only counterparts. It is shown that the real-time GPS/Galileo PPP can achieve a sub-decimeter horizontal positioning accuracy and about meter-level vertical positioning accuracy through the use of NAVCAST real-time corrections.

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“…With the rapid development of Global Navigation Satellite System (GNSS), real-time precise point positioning (RT PPP) with integer ambiguities resolution is possible thanks to the real-time precise orbits, clocks, and code/phase biases products of satellites, provided freely by the Center National d'Etudes Spatiales (CNES) [1]. These real-time products in the CLK93/CLK92 stream have been broadcasted by the CNES real-time analysis center since 14/09/2014 [2]. Based on these products, the integer property of user ambiguities can be recovered to improve positioning accuracy and reliability.…”

Section: Introductionmentioning

confidence: 99%

A New Weighting Approach with Application to Ionospheric Delay Constraint for GPS/GALILEO Real-Time Precise Point Positioning

Liu

Wang

et al. 2018

Applied Sciences

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The real-time precise point positioning (RT PPP) technique has attracted increasing attention due to its high-accuracy and real-time performance. However, a considerable initialization time, normally a few hours, is required in order to achieve the proper convergence of the real-valued ambiguities and other estimate parameters. The RT PPP convergence time may be reduced by combining quad-constellation global navigation satellite system (GNSS), or by using RT ionospheric products to constrain the ionosphere delay. But to improve the performance of convergence and achieve the best positioning solutions in the whole data processing, proper and precise variances of the observations and ionospheric constraints are important, since they involve the processing of measurements of different types and with different accuracy. To address this issue, a weighting approach is proposed by a combination of the weight factors searching algorithm and a moving-window average filter. In this approach, the variances of ionospheric constraints are adjusted dynamically according to the principle that the sum of the quadratic forms of weighted residuals is the minimum, and the filter is applied to combine all epoch-by-epoch weight factors within a time window. To evaluate the proposed approach, datasets from 31 Multi-GNSS Experiment (MGEX) stations during the period of DOY (day of year) 023-054 in 2018 are analyzed with different positioning modes and different data processing methods. Experimental results show that the new weighting approach can significantly improve the convergence performance, and that the maximum improvement rate reaches 35.9% in comparison to the traditional method of priori variance in the static dual-frequency positioning mode. In terms of the RMS (Root Mean Square) statistics of positioning errors calculated by the new method after filter convergence, the same accuracy level as that of RT PPP without constraints can be achieved.

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Performance assessment of multi-GNSS real-time PPP over Iran

Cited by 34 publications

References 32 publications

Research on time difference detection algorithm based on combination of GNSS and PPP

Research on time difference detection algorithm based on combination of GNSS and PPP

Real-Time GPS/Galileo Precise Point Positioning Using NAVCAST Real-Time Corrections

A New Weighting Approach with Application to Ionospheric Delay Constraint for GPS/GALILEO Real-Time Precise Point Positioning

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