New Characteristics of Geometric Dilution of Precision (GDOP) for Multi-GNSS Constellations

2014 ◽  
Vol 67 (6) ◽  
pp. 1018-1028 ◽  
Author(s):  
Yunlong Teng ◽  
Jinling Wang
Keyword(s):  
Single Point ◽  
Satellite System ◽  
Navigation Satellite ◽  
Dilution Of Precision ◽  
Single Point Positioning ◽  
Point Positioning ◽  
Geometric Dilution Of Precision ◽  
Global Navigation Satellite ◽  
Gnss Constellation ◽  
Selection Of

For multi-Global Navigation Satellite System (GNSS) constellations, the Geometric Dilution of Precision (GDOP) is an important parameter utilised for the selection of satellites. This paper has derived new formulae to describe the change of GDOP. The result shows that, for GNSS single point positioning solutions, if one more satellite belonging to the existing tracked multi-GNSS constellation used in the single point positioning solution is added, the GDOP always decreases with the number of the added satellites. On the other hand, when the constellation of the added satellite is not from the tracked existing constellations, the different numbers of the added satellites have different influences on the change of GDOP. Generally, adding one satellite from another constellation into the existing multi-GNSS constellations will increase the GDOP, but adding two satellites will decrease the GDOP compared with adding one from another constellation. Additionally, the GDOP also increases in the cases of adding two satellites from two different constellations into the tracked existing constellations.

scholarly journals Code Single Point Positioning Using Nominal Gnss Constellations (Future Perception)

2007 ◽  
Vol 42 (3) ◽  
pp. 149-153
Author(s):  
A. Farah
Keyword(s):  
Single Point ◽  
Satellite System ◽  
Global Navigation Satellite Systems ◽  
Navigation Satellite ◽  
Satellite Systems ◽  
Performance Improvements ◽  
Single Point Positioning ◽  
Global Navigation ◽  
Point Positioning ◽  
Global Navigation Satellite

Code Single Point Positioning Using Nominal Gnss Constellations (Future Perception) Global Navigation Satellite Systems (GNSS) have an endless number of applications in industry, science, military, transportation and recreation & sports. Two systems are currently in operation namely GPS (the USA Global Positioning System) and GLONASS (the Russian GLObal NAvigation Satellite System), and a third is planned, the European satellite navigation system GALILEO. The potential performance improvements achievable through combining these systems could be significant and expectations are high. The need is inevitable to explore the future of positioning from different nominal constellations. In this research paper, Bernese 5.0 software could be modified to simulate and process GNSS observations from three different constellations (GPS, Glonass and Galileo) using different combinations. This study presents results of code single point positioning for five stations using the three constellations and different combinations.

scholarly journals Research on satellite selection algorithm in ship positioning based on both geometry and geometric dilution of precision contribution

2019 ◽  
Vol 16 (1) ◽  
pp. 172988141983024 ◽  
Author(s):  
Pengfei Zhang
Keyword(s):  
Computational Complexity ◽  
Navigation System ◽  
Satellite System ◽  
Navigation Satellite ◽  
Selection Algorithm ◽  
Dilution Of Precision ◽  
Satellite Navigation System ◽  
Satellite Selection ◽  
Geometric Dilution Of Precision ◽  
Global Navigation Satellite

With the networking of four Global Navigation Satellite Systems, the combination of multi-constellation applications has become an inevitable trend, and there will be more and more visible satellites that can be participated in ship positioning. However, the computational complexity increases sharply, which greatly improves the load capacity of the receiver’s data processor and reduces the output frequency of the positioning result. To achieve the balance between positioning accuracy and computational complexity, a new fast satellite selection algorithm based on both of geometry and geometric dilution of precision contribution is proposed. Firstly, this article analyzes the geometry characteristics of the least visible satellites has minimum geometric dilution of precision that meet the positioning requirements and makes clear the layout of their elevation angles and azimuth angles. In addition, it derives the relationship of geometric dilution of precision and the visible satellites layout and gets geometric dilution of precision contribution of each satellite. Finally, based on the observation data of JFNG tracking station of the Multi-Global Navigation Satellite System (GNSS) Experiment trial network, the positioning error and the elapsed time of GPS/Beidou Satellite Navigation System and GPS/Beidou Satellite Navigation System/Russian Global Orbiting Navigation Satellite System (GLOANSS) are compared. Simulation results show that the algorithm solves the problem that there are a lot of matrix multiplications and matrix inversions in the traditional satellite selection algorithm, and the new algorithm can reduce computational complexity and increase receiver processing speed.

scholarly journals Reducing the Effect of Positioning Errors on Kinematic Raw Doppler (RD) Velocity Estimation Using BDS-2 Precise Point Positioning

Sensors ◽  
2019 ◽  
Vol 19 (13) ◽  
pp. 3029 ◽  
Author(s):  
Duan ◽  
Sun ◽  
Ouyang ◽  
Chen ◽  
Shi
Keyword(s):  
Precise Point Positioning ◽  
Single Point ◽  
Estimation Method ◽  
Satellite System ◽  
Velocity Estimation ◽  
Navigation Satellite ◽  
Positioning Accuracy ◽  
Positioning Errors ◽  
Point Positioning ◽  
Global Navigation Satellite

In the traditional raw Doppler (RD) velocity estimation method, the positioning error of the pseudorange-based global navigation satellite system (GNSS) single point positioning (SPP) solution affects the accuracy of the velocity estimation through the station-satellite unit cosine vector. To eliminate the effect of positioning errors, this paper proposes a carrier-phase-based second generation of the BeiDou navigation satellite system (BDS-2) precise point positioning (PPP) RD velocity estimation method. Compared with the SPP positioning accuracy of tens of meters, the BDS-2 kinematic PPP positioning accuracy is significantly improved to the dm level. In order to verify the reliability and applicability of the developed method, three dedicated tests, the vehicle-borne, ship-borne and air-borne platforms, were conducted. In the vehicle-borne experiment, the GNSS and inertial navigation system (INS)-integrated velocity solution was chosen as the reference. The velocity accuracy of the BDS-2 PPP RD method was better than that of SPP RD by 28.4%, 27.1% and 26.1% in the east, north and up directions, respectively. In the ship-borne and air-borne experiments, the BDS-2 PPP RD velocity accuracy was improved by 17.4%, 21.4%, 17.8%, and 38.1%, 17.6%, 17.5% in the same three directions, respectively, compared with the BDS-2 SPP RD solutions. The reference in these two tests is the real-time kinematic (RTK) Position Derivation (PD)-based velocity.

scholarly journals GEOMETRIC DILUTION OF PRECISION OF THE GNSS FOR MARS (GNSS FATIMA)

Aviation ◽  
2016 ◽  
Vol 20 (4) ◽  
pp. 183-190
Author(s):  
Jozef KOZAR ◽  
Stanislav DURCO ◽  
Frantisek ADAMCIK
Keyword(s):  
Satellite System ◽  
Navigation Satellite ◽  
Positioning Systems ◽  
Dilution Of Precision ◽  
Positioning Errors ◽  
Factors Influencing ◽  
Main Factors ◽  
Geometric Dilution Of Precision ◽  
Global Navigation Satellite ◽  
Critical Aspects

Positioning on Mars is one of the critical aspects of every planetary mission. Current complex planetary exploration systems (orbital and surface) rely on complex navigation and positioning systems, which make these systems complicated, expensive and their missions dangerous. The project of the global navigation satellite system for Mars (proposed system name – FATIMA) can make this and even future manned missions more safe, less expensive and the whole positioning in real time more reliable. The GNSS can be used by more systems or users simultaneously. In this research paper we focus on possible positioning errors when such a system is used. This research is focused on the GDOP – Geometric Dilution of Precision as one of the main factors influencing the GNSS.

scholarly journals Real-Time Precise Point Positioning Using Orbit and Clock Corrections as Quasi-Observations for Improved Detection of Faults

2018 ◽  
Vol 71 (4) ◽  
pp. 769-787 ◽  
Author(s):  
Ahmed El-Mowafy
Keyword(s):  
Real Time ◽  
Precise Point Positioning ◽  
Exclusion Process ◽  
Satellite Orbit ◽  
Satellite System ◽  
Navigation Satellite ◽  
System Service ◽  
Point Positioning ◽  
Predicted Values ◽  
Global Navigation Satellite

Real-time Precise Point Positioning (PPP) relies on the use of accurate satellite orbit and clock corrections. If these corrections contain large errors or faults, either from the system or by meaconing, they will adversely affect positioning. Therefore, such faults have to be detected and excluded. In traditional PPP, measurements that have faulty corrections are typically excluded as they are merged together. In this contribution, a new PPP model that encompasses the orbit and clock corrections as quasi-observations is presented such that they undergo the fault detection and exclusion process separate from the observations. This enables the use of measurements that have faulty corrections along with predicted values of these corrections in place of the excluded ones. Moreover, the proposed approach allows for inclusion of the complete stochastic information of the corrections. To facilitate modelling of the orbit and clock corrections as quasi-observations, International Global Navigation Satellite System Service (IGS) real-time corrections were characterised over a six-month period. The proposed method is validated and its benefits are demonstrated at two sites using three days of data.

scholarly journals Multi-GNSS Combined Precise Point Positioning Using Additional Observations with Opposite Weight for Real-Time Quality Control

2019 ◽  
Vol 11 (3) ◽  
pp. 311 ◽  
Author(s):  
Wenju Fu ◽  
Guanwen Huang ◽  
Yuanxi Zhang ◽  
Qin Zhang ◽  
Bobin Cui ◽  
...  
Keyword(s):  
Quality Control ◽  
Real Time ◽  
Precise Point Positioning ◽  
Satellite System ◽  
Convergence Time ◽  
Navigation Satellite ◽  
Positioning Accuracy ◽  
Global Navigation ◽  
Point Positioning ◽  
Global Navigation Satellite

The emergence of multiple global navigation satellite systems (multi-GNSS), including global positioning system (GPS), global navigation satellite system (GLONASS), Beidou navigation satellite system (BDS), and Galileo, brings not only great opportunities for real-time precise point positioning (PPP), but also challenges in quality control because of inevitable data anomalies. This research aims at achieving the real-time quality control of the multi-GNSS combined PPP using additional observations with opposite weight. A robust multiple-system combined PPP estimation is developed to simultaneously process observations from all the four GNSS systems as well as single, dual, or triple systems. The experiment indicates that the proposed quality control can effectively eliminate the influence of outliers on the single GPS and the multiple-system combined PPP. The analysis on the positioning accuracy and the convergence time of the proposed robust PPP is conducted based on one week’s data from 32 globally distributed stations. The positioning root mean square (RMS) error of the quad-system combined PPP is 1.2 cm, 1.0 cm, and 3.0 cm in the east, north, and upward components, respectively, with the improvements of 62.5%, 63.0%, and 55.2% compared to those of single GPS. The average convergence time of the quad-system combined PPP in the horizontal and vertical components is 12.8 min and 12.2 min, respectively, while it is 26.5 min and 23.7 min when only using single-GPS PPP. The positioning performance of the GPS, GLONASS, and BDS (GRC) combination and the GPS, GLONASS, and Galileo (GRE) combination is comparable to the GPS, GLONASS, BDS and Galileo (GRCE) combination and it is better than that of the GPS, BDS, and Galileo (GCE) combination. Compared to GPS, the improvements of the positioning accuracy of the GPS and GLONASS (GR) combination, the GPS and Galileo (GE) combination, the GPS and BDS (GC) combination in the east component are 53.1%, 43.8%, and 40.6%, respectively, while they are 55.6%, 48.1%, and 40.7% in the north component, and 47.8%, 40.3%, and 34.3% in the upward component.

Lower Bounds on DOP

2017 ◽  
Vol 70 (5) ◽  
pp. 1041-1061 ◽  
Author(s):  
Peter F. Swaszek ◽  
Richard J. Hartnett ◽  
Kelly C. Seals
Keyword(s):  
Lower Bounds ◽  
Global Navigation Satellite System ◽  
Satellite System ◽  
Navigation Satellite ◽  
Satellite Constellations ◽  
Dilution Of Precision ◽  
Gnss Positioning ◽  
Satellite Selection ◽  
Global Navigation ◽  
Global Navigation Satellite

Code phase Global Navigation Satellite System (GNSS) positioning performance is often described by the Geometric or Position Dilution of Precision (GDOP or PDOP), functions of the number of satellites employed in the solution and their geometry. This paper develops lower bounds to both metrics solely as functions of the number of satellites, effectively removing the added complexity caused by their locations in the sky, to allow users to assess how well their receivers are performing with respect to the best possible performance. Such bounds will be useful as receivers sub-select from the plethora of satellites available with multiple GNSS constellations. The bounds are initially developed for one constellation assuming that the satellites are at or above the horizon. Satellite constellations that essentially achieve the bounds are discussed, again with value toward the problem of satellite selection. The bounds are then extended to a non-zero mask angle and to multiple constellations.

scholarly journals Testing of Software for the Planning of a Linear Object GNSS Measurement Campaign under Simulated Conditions

Energies ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7896
Author(s):  
Sławomir Figiel ◽  
Cezary Specht ◽  
Marek Moszyński ◽  
Andrzej Stateczny ◽  
Mariusz Specht
Keyword(s):  
Global Navigation Satellite System ◽  
Satellite System ◽  
Navigation Satellite ◽  
Dilution Of Precision ◽  
Measurement Campaign ◽  
Average Value ◽  
Linear Object ◽  
Global Navigation ◽  
On The Road ◽  
Global Navigation Satellite

The precision of a linear object measurement using satellite techniques is determined by the number and the relative position of the visible satellites by the receiver. The status of the visible constellation is described by the Dilution Of Precision (DOP). The obtained geometric coefficient values are dependent on many variables. When determining these values, field obstacles at the receiver location and satellite positions changing with time must be taken into account. Carrying out a series of surveys as part of a linear object Global Navigation Satellite System (GNSS) measurement campaign requires the optimisation problem to be solved. The manner of the inspection vehicle’s movement should be determined in such a way that the surveys are taken only within the pre-defined time frames and that the geometric coefficient values obtained at subsequent points of the route are as low as possible. The purpose of this article is to develop a software for the planning of a linear object GNSS measurement campaign to implemented in motion and taking into account the terrain model and its coverage. Additionally, it was determined how much the developed program improves DOP values on the planned route under simulated conditions. This software has no equivalent elsewhere in the world, as the current solutions for the planning of a GNSS measurement campaign, e.g., Trimble GNSS Planning, GNSS Mission Planning, or GPS Navigation Toolbox, allow the satellite constellation geometry to be analysed exclusively for specific coordinates and at a specific time. Analysis of the obtained simulation test results indicates that the campaign implementation in accordance with the pre-determined schedule significantly improves the quality of the recorded GNSS data. This is particularly noticeable when determining the position using the Global Positioning System (GPS) and GLObal NAvigation Satellite System (GLONASS) satellite constellations at the same time. During the tests conducted on the road along a three-kilometre-long route (tram loop) in Gdańsk Brzeźno, the average value of the obtained Position Dilution Of Precision (PDOP) decreased by 22.17% thanks to using the software to plan a linear object GNSS measurement campaign. The largest drop in the geometric coefficient values was noted for an area characterised by a very large number of field obstacles (trees with crowns and high buildings). Under these conditions, the PDOP value decreased by approx. 25%. In areas characterised by a small number of field obstacles (single trees in the vicinity of the track, clusters of trees and buildings located along the track), the changes in the PDOP were slightly smaller and amounted to several percent.

Aircraft positioning using GPS/GLONASS code observations

2019 ◽  
Vol 92 (2) ◽  
pp. 163-171 ◽  
Author(s):  
Kamil Krasuski ◽  
Janusz Cwiklak ◽  
Marek Grzegorzewski
Keyword(s):  
Global Navigation Satellite System ◽  
Single Point ◽  
Satellite System ◽  
Least Square ◽  
Navigation Satellite ◽  
Navigation Systems ◽  
Protection Level ◽  
Content Type ◽  
Global Navigation ◽  
Global Navigation Satellite

Purpose This paper aims to present the problem of the integration of the global positioning system (GPS)/global navigation satellite system (GLONASS) data for the processing of aircraft position determination. Design/methodology/approach The aircraft coordinates were obtained based on GPS and GLONASS code observations for the single point positioning (SPP) method. The numerical computations were executed in the aircraft positioning software (APS) package. The mathematical scheme of equation observation of the SPP method was solved using least square estimation in stochastic processing. In the research experiment, the raw global navigation satellite system data from the Topcon HiperPro onboard receiver were applied. Findings In the paper, the mean errors of an aircraft position from APS were under 3 m. In addition, the accuracy of aircraft positioning was better than 6 m. The integrity term for horizontal protection level and vertical protection level parameters in the flight test was below 16 m. Research limitations/implications The paper presents only the application of GPS/GLONASS observations in aviation, without satellite data from other navigation systems. Practical implications The presented research method can be used in an aircraft based augmentation system in Polish aviation. Social implications The paper is addressed to persons who work in aviation and air transport. Originality/value The paper presents the SPP method as a satellite technique for the recovery of an aircraft position in an aviation test.

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