Evaluation of GPS/Galileo RTK Network Configuration: Case Study in Greece

Tsakiri, Maria

doi:10.1061/(asce)su.1943-5428.0000054

Cited by 5 publications

(3 citation statements)

References 21 publications

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“…In terms of temporal correlation for NRTK methods, it was shown that there is no significant difference for interstation distances of between 15 and 45 kilometres (Ogutcu, 2019). Other studies have observed that GALILEO and GLONASS usage with GPS has positive impacts on integer ambiguity solution and TTFA (Ogutcu and Kalayci, 2016;Tsakiri, 2011).…”

Section: Introductionmentioning

confidence: 93%

Effects of the Continuously Operating Reference Station (CORS) network on the accuracy, precision, and Time to Fix Ambiguity (TTFA) performance

Gökdaş¹,

Ozludemir²

2022

Earth sci. res. j.

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The geometric design of the Continuously Operating Reference Station (CORS) network is one of the most critical factors that impact accuracy, precision, and Time to Fix Ambiguity (TTFA) performance. In this study, the authors investigate the subject of geometric design by using both local ISKI CORS and national CORS-Turkey (CORS-TR) networks, and they redesign the ISKI CORS network by increasing interstation distances. For three systems, real-time Virtual Reference Station (VRS) solutions have been obtained and tested with Analysis of Variance (ANOVA). As a result, the 8-station ISKI CORS provides the most accurate results in the vertical component. In contrast, for TTFA performance, the CORS-TR network shows worse outcomes than the others. Due to the increase in the interstation distances, the increase in the base length caused worse results in FIX solution ratios for redesigned ISKI CORS. In summary, the authors have stated that the 8-station ISKI CORS network performs better, especially regarding vertical accuracy. Furthermore, the authors state that the TTFA performance and FIX solution ratios are high, and the ISKI CORS geometric design is optimal.

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Section: Introductionmentioning

confidence: 93%

Effects of the Continuously Operating Reference Station (CORS) network on the accuracy, precision, and Time to Fix Ambiguity (TTFA) performance

Gökdaş¹,

Ozludemir²

2022

Earth sci. res. j.

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“…The performance of GPS/Galileo was evaluated through simulation in terms of global availability, accuracy, and reliability [16]. The performance of a GPS/Galileo network-based real-time kinematic was evaluated by assessing the success rates of correct integer ambiguity resolution with simulation software [17].…”

Section: Introductionmentioning

confidence: 99%

Galileo Augmenting GPS Single-Frequency Single-Epoch Precise Positioning with Baseline Constrain for Bridge Dynamic Monitoring

et al. 2019

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The Single-frequency Single-epoch double-differenced baseline resolution technique of Global Positioning System (GPS) provides a good opportunity for monitoring the displacement or deflection behavior of bridges under different loading conditions in real-time. However, for single GPS, a high success rate baseline solution is difficult to achieve due to the lack of sufficient visible satellites and the low accuracy of float solutions. Galileo Satellite Navigation System (Galileo) has 14 medium earth orbit satellites (as of May 2018) that can be used to supplement GPS. The frequency bands of Galileo overlap with that of GPS on E1/L1 and E5a/L5, which is conducive to the combination of observations in integration positioning. Accordingly, Galileo augmenting GPS is an effective and necessary approach to improve the positioning availability and reliability. Moreover, using the baseline length constraint can improve the accuracy of float solutions, narrow the search space, and finally increase the success rate of ambiguity resolution and positioning. The single-frequency single-epoch double-differenced GPS/Galileo mathematical model with baseline length constraint is deduced in this paper. Two sets of GNSS real bridge data were used for further analysis on the improvement of GPS/Galileo with baseline length constraint when compared to single GPS. Finally, a Fast Fourier Transformation (FFT) algorithm was adopted for precisely detecting the local dominant frequencies of XB, YB, and ZB direction of the two stations.

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“…In Germany, the realtime service SAPOS HEPS was one of the first RTKservices using the Network RTK approach (Wegener and Wanninger, 2005). Other examples of active networks in Europe are found in Edwards et al (2010), Tsakiri (2011) or (Bakula, 2013) to name a few. RTK networks complement the national geodetic infrastructure in these countries.…”

Section: National and Local Active Network In Souther Spainmentioning

confidence: 99%

Are local active networks a reliable densification of national RTK positioning network? A case study in Spain

Garrido¹

2017

Acta Geodynamica Et Geomaterialia

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The use of Continuously Operating Reference Stations, both singly and as part of an active network, is widely employed in surveying, engineering and other geomatics applications, achieving high accuracy positioning even in real time. With an active network the measurements of the reference stations are processed jointly in order to model the errors and compute network RTK corrections. Due to distance dependent errors (ionospheric and tropospheric delays), single base RTK positioning accuracy decreases with increased baseline length. However, the network solution (NRTK) retains the accuracy and the time to fix ambiguities (TTFA) at a constant level. This study aims to contribute to the scientific research on real time positioning based on active networks. In Southern Spain, ERGNSS, a national CORS network that provides GNSS data for post-processing and real time single-based reference station corrections, shares territory with the Andalusian Positioning Network (RAP), a local active network. RAP provides network and single-based RTK corrections. In order to analyze the quality of real time positioning based on both networks, several tests have been performed on a sample of test points. The reference frame, the time to fix ambiguity resolution, precision, accuracy and repeatability of RTK positioning are considered as the evaluation parameters. The results confirm that the RAP network complements the precise positioning services provided by the ERGNSS network, ensuring accurate real time positioning, full coverage and reliable positioning services in the Andalusian Community. operating reference station. With a CORS network the measurements of several reference stations are processed jointly in order to model the GNSS measurement errors and to compute network RTK corrections for the coverage area of the active network. While a sparse CORS network is sufficient for datum definition, the distance among permanent stations is limited to few tens of kilometers (50 -60 km) to model the distance dependent errors. Wang et al. (2010) show that in areas where there are insufficient users to justify high densities of CORS stations, it may be possible to offer RTK services using more sparse networks. ARTICLE INFOThe main advantages of an active network are: it requires a lower density of reference stations, it is more robust with respect to possible failures in a particular reference station, it improves work performance and it transmits a reference frame throughout the coverage area of the network. Different manufacturers provide slightly different concepts for network RTK corrections. The most widely used solutions are the FKP (Flächen-korrektur-parameter), the VRS (Virtual Reference Station) and the MAC (Master Auxiliary Concept) approach (Euler et al., 2001). Based on the latter, Leica Geosystems© offers MAX and i-MAX solutions (Takac and Zelder, 2008).

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Evaluation of GPS/Galileo RTK Network Configuration: Case Study in Greece

Cited by 5 publications

References 21 publications

Effects of the Continuously Operating Reference Station (CORS) network on the accuracy, precision, and Time to Fix Ambiguity (TTFA) performance

Effects of the Continuously Operating Reference Station (CORS) network on the accuracy, precision, and Time to Fix Ambiguity (TTFA) performance

Galileo Augmenting GPS Single-Frequency Single-Epoch Precise Positioning with Baseline Constrain for Bridge Dynamic Monitoring

Are local active networks a reliable densification of national RTK positioning network? A case study in Spain

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