Revisiting the Role of Observation Session Duration on Precise Point Positioning Accuracy Using Gipsy/Oasis Ii Software

Hayal, Adem G.; Şanli, D. Uğur

doi:10.1590/s1982-21702016000300023

Cited by 8 publications

(5 citation statements)

References 23 publications

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“…Third, GIPSY single-receiver ambiguity resolution further improved the accuracy of PPP (Bertiger et al, 2010). Bertiger et al (2010) and Hayal and Sanli (2016) showed how positioning accuracy was improved with reprocessed JPL products and single-receiver ambiguity resolution. Reprocessing especially improved the east component and this is correlated with the findings in this paper.…”

Section: Resultsmentioning

confidence: 95%

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Assessment of geodetic velocities using GPS campaign measurements over long baseline lengths

Duman

Şanli

2019

Nat. Hazards Earth Syst. Sci.

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Abstract. GPS campaign measurements are frequently used in order to determine geophysical phenomena such as tectonic motion, fault zones, landslides, and volcanoes. When observation duration is shorter, the accuracy of coordinates are degraded and the accuracy of point velocities are affected. The accuracies of the geodetic site velocities from a global network of International GNSS Service (IGS) stations were previously investigated using only PPP. In this study, we extend which site velocities will also be assessed, including fundamental relative positioning. PPP-derived results will also be evaluated to see the effect of reprocessed JPL products, single-receiver ambiguity resolution, repeating survey campaigns minimum 3 days at the site, and eliminating noisier solutions prior to the year 2000. To create synthetic GPS campaigns, 18 globally distributed, continuously operating IGS stations were chosen. GPS data were processed comparatively using GAMIT/GLOBK v10.6 and GIPSY-OASIS II v6.3. The data of synthetic campaign GPS time series were processed using a regression model accounting for the linear and seasonal variation of the ground motion. Once the velocities derived from 24 h sessions were accepted as the truth, the results from sub-sessions were compared with the results of 24 h and hypothesis testing was applied for the significance of the differences. The major outcome of this study is that on global scales (i.e. over long distances) with short observation sessions, the fundamental relative positioning produces results similar to PPP. The reliability of the velocity estimation for GPS horizontal baseline components has now been improved to about 85 % of the average for observation durations of 12 h.

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Section: Resultsmentioning

confidence: 95%

“…Second, the analysis was performed with reprocessed orbits and clocks. JPL changed its orbit and clock estimation strategy as of the year 2007 (Hayal and Sanli, 2016). Third, GIPSY single-receiver ambiguity resolution further improved the accuracy of PPP (Bertiger et al, 2010).…”

Section: Resultsmentioning

confidence: 99%

Assessment of geodetic velocities using GPS campaign measurements over long baseline lengths

Duman

Şanli

2019

Nat. Hazards Earth Syst. Sci.

View full text Add to dashboard Cite

show abstract

“…Second, the analysis was performed with reprocessed orbits and clocks. JPL changed its orbit and clock estimation strategy as of the year 2007 (Hayal and Sanli, 2016). Third, GIPSY single receiver ambiguity resolution was further improved the accuracy of PPP (Bertiger et.…”

Section: Resultsmentioning

confidence: 99%

“…al. (2010) and Hayal and Sanli (2016) showed how positioning accuracy was improved with reprocessed JPL products and single receiver ambiguity resolution. Reprocessing especially improved the east component and this is correlated with the findings in this paper.…”

Section: Resultsmentioning

confidence: 99%

Accuracy of geodetic site velocities from repeated GPS measurements: relative positioning over long baselines

Duman

Şanli

2018

Preprint

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Abstract. Currently, GPS campaign measurements (i.e. repeated GPS measurements) are used frequently in order to determine geophysical phenomena such as tectonic motion, fault zones, landslides, and volcanoes. The coordinates of a new point installed in a study area are usually found either by using relative point positioning or precise point positioning (PPP). Employing observation sessions shorter than 24 h might still be a necessity at times. When observation duration is shorter, the accuracy of coordinates are degraded and also the accuracy of point velocities are affected. The accuracies of the geodetic site velocities from a global network of the International GNSS Service (IGS) stations were previously investigated using only PPP. In this study, we extend that study in which site velocities will also be assessed including fundamental relative positioning. PPP derived results will also be evaluated to see the effect of JPL reprocessed products and single receiver ambiguity resolution. IGS is a good data source for simulation studies and hence globally distributed 18 continuously operating IGS stations were chosen to create synthetic GPS campaigns. GPS data were processed comparatively using GAMIT/GLOBK v10.6 and GIPSY/OASIS II v6.3. The data of synthetic campaign GPS time series were processed using a regression model accounting for the linear and seasonal variation of the ground motion. Once accepting the velocities derived from 24 h sessions as the truth, the results from sub-sessions were compared with the results of 24 h and hypothesis testing was applied for the significance of the differences. The major outcome of this study is that at global scales (i.e. over long distances) with short observation sessions, the fundamental relative positioning produces similar results to PPP. The reliability of the velocity estimation for horizontal components has now been improved to about 85 % on the average for observation durations of 12 h.

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“…With the developments of Global Positioning Service (GPS) satellite orbit and clock products, precise point positioning (PPP) could provide absolute positioning with millimetre (1-2 mm) and sub-centimetre level (4-6 mm) precision of daily solutions for horizontal and vertical components, respectively (Hayal andSanli, 2016, Gao andChen, 2004). PPP is gaining more popularity in the surveying community due to the simple and costeffective approach.…”

Section: Introductionmentioning

confidence: 99%

Performance assessment of IGS Combined/JPL individual rapid and ultra-rapid products: consideration of precise point positioning technique

Öğütçü

2020

International Journal of Engineering and Geosciences

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Satellite orbit and clock products are the key elements for precise point positioning (PPP). Contrary to the relative technique, errors in satellite orbit and clock directly lump to the station coordinates for PPP technique. Currently final, rapid and ultra-rapid (observed-half and predicted-half) satellite products have been made freely available over the internet mainly for Global Positioning Service (GPS) satellites. Final and rapid products are used for post-processing applications. For real-time and near real-time applications, ultra-rapid products with predicted and observed parts can be used. There are several analysis centers that provide the satellite orbit and clock products. In this paper, accuracy and precision of GPS rapid and ultra-rapid satellite orbit and clock products from two services, International Global Navigation Satellite Service (IGS) and Jet Propulsion Laboratory (JPL), were investigated in the position domain of PPP technique while the final products of these services were taken as the true value. Ten IGS stations around the world were chosen for PPP processes. 24-12-8-4-2 hours of non-overlapping arc-lengths of GPS observations in 31 consecutive days (DOY 1-31 of 2018) were processed for each station. The results confirm that the shorter the arc-lengths, the larger the relative error of rapid and ultra-rapid products due to the similar Gaussian distribution pattern of the orbit errors with respect to the final products. In terms of consistency between the products, Root-Mean-Square-Errors (RMSE) of final-rapid differences of IGS and JPL are at the millimeter level. Millimeter level accuracy can be obtained using rapid and ultra-rapid products for JPL whereas only rapid products of IGS maintain millimeter accuracy with respect to the final products.

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Revisiting the Role of Observation Session Duration on Precise Point Positioning Accuracy Using Gipsy/Oasis Ii Software

Cited by 8 publications

References 23 publications

Assessment of geodetic velocities using GPS campaign measurements over long baseline lengths

Assessment of geodetic velocities using GPS campaign measurements over long baseline lengths

Accuracy of geodetic site velocities from repeated GPS measurements: relative positioning over long baselines

Performance assessment of IGS Combined/JPL individual rapid and ultra-rapid products: consideration of precise point positioning technique

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