Analysis of the Egnos Ionospheric Model and Its Impact on the Integrity Level in the Central Eastern Europe Region

Lupsic, Balazs; Takács, Barnabás

doi:10.5194/isprs-archives-xlii-4-w14-159-2019

Cited by 5 publications

(3 citation statements)

References 9 publications

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“…A somewhat different genesis of creation, in relation to the global Klobuchar and NeQuick models, is characterised by the local ionosphere models used by SBAS (Satellite-Based Augmentation System) systems. The ionospheric delay in SBAS systems has been the subject of many previous scientific studies [33][34][35]. Thanks to the fact that these models are created in real time (updated every 5 min), they can be applied for safety-of-life applications such as aviation, where there is a need for a high integrity of data; thus, positioning based on information only from GPS/GLONASS (Global Positioning System/GLObal NAvigation Satellite System) systems [36] is not satisfactory for the aviation users.…”

Section: Ionospheric Models Used For Single-frequency Gnss Receiversmentioning

confidence: 99%

Klobuchar, NeQuick G, and EGNOS Ionospheric Models for GPS/EGNOS Single-Frequency Positioning under 6–12 September 2017 Space Weather Events

Ciećko

Grunwald

2020

Applied Sciences

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The ionosphere is one of the main factors affecting the accuracy of global navigation satellite systems (GNSS). It is a dispersive medium for radio signals, and for multi-frequency receivers, most of its effect can be removed. The problem is for the single-frequency devices, which must rely on a correction model. The motivation of this paper is the adoption of different ionospheric models in GPS/EGNOS (Global Positioning System/European Geostationary Navigation Overlay Service) positioning to mitigate the impact of geomagnetic storms. The aim of this article is to examine the accuracy of GPS/EGNOS single-frequency positioning. In all the examined solutions, GPS L1 data augmented with the EGNOS clock and ephemeris corrections were used in position calculation. The changes were only made to the ionospheric model. The examined scenarios are as follows: without any model (off), Klobuchar, NeQuick G, and EGNOS model. The analysed period is 6–12 September 2017, during which the last strong geomagnetic storm took place. In order to perform a reliable analysis, the study was conducted at three International GNSS Service (IGS) stations in different geographical latitudes, within the EGNOS APV-1 (Approach with Vertical Guidance) availability border. The obtained results prove that the EGNOS ionospheric model meets the aviation positioning accuracy criteria for the APV-1 approach during the studied geomagnetic storm. The EGNOS average horizontal positioning error of 0.75 m was on average almost two times lower than the other solutions. For vertical positioning, the EGNOS error of 0.93 m proved to be two times lower than those of the Klobuchar and NeQuick G models, while it was more than three times lower for the off solution.

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Section: Ionospheric Models Used For Single-frequency Gnss Receiversmentioning

confidence: 99%

Klobuchar, NeQuick G, and EGNOS Ionospheric Models for GPS/EGNOS Single-Frequency Positioning under 6–12 September 2017 Space Weather Events

Ciećko

Grunwald

2020

Applied Sciences

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“…In aeronautical GPS/EGNOS applications, according to Radio Technical Committee for Aeronautics [ 30 ], it is possible to use the ionospheric model of the original EGNOS and the Klobuchar model known from GPS autonomous positioning. The original EGNOS model, like the models associated with other SBASs, is a real time model that, with an interval of 5 min, attempts to take into account the influence of the ionosphere on positioning [ 31 , 32 , 33 , 34 , 35 ]. To determine the influence of the ionosphere on GPS/EGNOS positioning, according to the guidelines presented in RTCA (2013), it is necessary to define the ionospheric pierce point (IPP), which is the intersection between the theoretical ionospheric layer at 350 km above the Earth’s surface and the line between the receiver and the satellite [ 36 ].…”

Section: Methodsmentioning

confidence: 99%

Analysis of GPS/EGNOS Positioning Quality Using Different Ionospheric Models in UAV Navigation

Grunwald

Ciećko

Kozakiewicz

et al. 2023

Sensors

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Unmanned aerial vehicles (UAVs) have become very popular tools for geoinformation acquisition in recent years. They have also been applied in many other areas of life. Their navigation is highly dependent on global navigation satellite systems (GNSS). The European Geostationary Navigation Overlay Service (EGNOS) is intended to support GNSSs during positioning, mainly for aeronautical applications. The research presented in this paper concerns the analysis of the positioning quality of a modified GPS/EGNOS algorithm. The calculations focus on the source of ionospheric delay data as well as on the aspect of smoothing code observations with phase measurements. The modifications to the algorithm concerned the application of different ionospheric models for position calculation. Consideration was given to the EGNOS ionospheric model, the Klobuchar model applied to the GPS system, the Klobuchar model applied to the BeiDou system, and the NeQuick model applied to the Galileo system. The effect of removing ionospherical corrections from GPS/EGNOS positioning on the results of the determination of positioning quality was also analysed. The results showed that the original EGNOS ionospheric model maintains the best accuracy results and a better correlation between horizontal and vertical results than the other models examined. The additional use of phase-smoothing of code observations resulted in maximum horizontal errors of approximately 1.3 m and vertical errors of approximately 2.2 m. It should be noted that the results obtained have local characteristics related to the area of north-eastern Poland.

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“…The very first initiative to monitor the achievable accuracy and integrity with EGNOS was performed by the EGNOS Data Collection Network (EDCN) project Soley et al (2004). EGNOS performance can be slightly degraded at the boundary of coverage area due to lack of reliable ionosphere modelling over the periphery Grunwald et al (2016) or Lupsic and Takács (2019).…”

Section: Introductionmentioning

confidence: 99%

Gauss process regression for real-time ionospheric delay estimation from GNSS observations

Lupsic

Takács

2022

Acta Geod Geophys

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The number of devices equipped with global satellite positioning has exceeded seven billion recently. There are a wide variety of receivers regarding their accuracy and reliability. Low cost, multi-frequency units have been released on the market latterly; however, the number of single-frequency receivers is still significant. Since their measurements are influenced by ionospheric delay, accurate ionosphere models are of utmost importance to reduce the effect. This paper summarizes how Gauss process regression (GPR) can be applied to derive near real-time regional ionosphere models using raw Global Navigation Satellite System (GNSS) observations of permanent stations. While Gauss process is widely used in machine learning, GPR is a nonparametric, Bayesian approach to regression. GPR has several benefits for ionosphere monitoring since it is quite robust and efficient to derive a grid model from data available in irregular set of ionospheric pierce points. The corresponding instrumental delays are estimated by a parallel Kalman filter. The presented algorithm can be applied near real-time, however the results are offline calculated and are compared to two high quality TEC map products. Based on the analysis, the accuracy of the GPR modell is in 2 TECu range. The developed methods could be efficiently applied in the field of autonomous vehicle navigation with meeting both accuracy and integrity requirements.

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Analysis of the Egnos Ionospheric Model and Its Impact on the Integrity Level in the Central Eastern Europe Region

Cited by 5 publications

References 9 publications

Klobuchar, NeQuick G, and EGNOS Ionospheric Models for GPS/EGNOS Single-Frequency Positioning under 6–12 September 2017 Space Weather Events

Klobuchar, NeQuick G, and EGNOS Ionospheric Models for GPS/EGNOS Single-Frequency Positioning under 6–12 September 2017 Space Weather Events

Analysis of GPS/EGNOS Positioning Quality Using Different Ionospheric Models in UAV Navigation

Gauss process regression for real-time ionospheric delay estimation from GNSS observations

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