Precise Point Positioning using Multi-Constellation GNSS Observations for Kinematic Applications

2015 ◽  
Vol 9 (1) ◽  
Author(s):  
Mahmoud Abd Rabbou ◽  
Ahmed El-Rabbany
Keyword(s):  
Urban Areas ◽  
Precise Point Positioning ◽  
Global Navigation Satellite Systems ◽  
Test Scenario ◽  
Satellite Systems ◽  
Satellite Geometry ◽  
Point Positioning ◽  
Kinematic Ppp ◽  
Gnss Measurements ◽  
Global Navigation Satellite

AbstractTraditional precise point positioning (PPP) is commonly based on un-differenced ionosphere-free linear combination of Global Positioning System (GPS) observations. Unfortunately, for kinematic applications, GPS often experiences poor satellite visibility or weak satellite geometry in urban areas. To overcome this limitation, we developed a PPP model, which combines the observations of three global navigation satellite systems (GNSS), namely GPS, GLONASS and Galileo. Both un-differenced and between-satellite single-difference (BSSD) ionosphere-free linear combinations of pseudorange and carrier phase GNSS measurements are processed. The performance of the combined GNSS PPP solution is compared with the GPS-only PPP solution using a real test scenario in downtown Kingston, Ontario. Inter-system biases between GPS and the other two systems are also studied and obtained as a byproduct of the PPP solution. It is shown that the addition of GLONASS observations improves the kinematic PPP solution accuracy in comparison with that of GPS-only solution. However, the contribution of adding Galileo observations is not significant due to the limited number of Galileo satellites launched up to date. In addition, BSSD solution is found to be superior to that of traditional un-differenced model.

scholarly journals GPS Precise Point Positioning with the Japanese Quasi-Zenith Satellite System LEX Augmentation Corrections

2015 ◽  
Vol 68 (4) ◽  
pp. 769-783 ◽  
Author(s):  
Suelynn Choy ◽  
Ken Harima ◽  
Yong Li ◽  
Mazher Choudhury ◽  
Chris Rizos ◽  
...  
Keyword(s):  
Real Time ◽  
Precise Point Positioning ◽  
Satellite System ◽  
Global Navigation Satellite Systems ◽  
Satellite Systems ◽  
Satellite Navigation System ◽  
Point Positioning ◽  
Navigation Signals ◽  
Kinematic Ppp ◽  
Global Navigation Satellite

The Japanese Quasi-Zenith Satellite System (QZSS) is a regional satellite navigation system capable of transmitting navigation signals that are compatible and interoperable with other Global Navigation Satellite Systems (GNSS). In addition to navigation signals, QZSS also transmits augmentation signals, e.g. the L-band Experimental (LEX) signal. The LEX signal is unique for QZSS in delivering correction messages such as orbits and clock information that enable real-time Precise Point Positioning (PPP). This study aims to evaluate the availability of the LEX signal as well as the quality of the broadcast correction messages for real-time PPP applications. The system is tested in both static and kinematic positioning modes. The results show that the availability of the LEX signal is 60% when the QZSS satellite elevation is at 30° and above 90% when the satellite is above 40° elevation. Centimetre-level position accuracy can be obtained for static PPP processing after two hours of convergence using the current MADOCA-LEX (Multi-GNSS Advanced Demonstration of Orbit and Clock Analysis) correction messages transmitted on the LEX signal; and decimetre-level point positioning accuracy can be obtained for kinematic PPP processing.

scholarly journals Filtering Link Outliers in Vehicle Trajectories by Spatial Reasoning

2021 ◽  
Vol 10 (5) ◽  
pp. 333
Author(s):  
Junli Liu ◽  
Miaomiao Pan ◽  
Xianfeng Song ◽  
Jing Wang ◽  
Kemin Zhu ◽  
...  
Keyword(s):  
Urban Areas ◽  
Spatial Reasoning ◽  
Sampling Interval ◽  
Global Navigation Satellite Systems ◽  
Quality Analysis ◽  
Ancillary Data ◽  
Satellite Systems ◽  
Positioning Errors ◽  
Vehicle Trajectories ◽  
Global Navigation Satellite

Vehicle trajectories derived from Global Navigation Satellite Systems (GNSS) are used in various traffic applications based on trajectory quality analysis for the development of successful traffic models. A trajectory consists of points and links that are connected, where both the points and links are subject to positioning errors in the GNSS. Existing trajectory filters focus on point outliers, but neglect link outliers on tracks caused by a long sampling interval. In this study, four categories of link outliers are defined, i.e., radial, drift, clustered, and shortcut; current available algorithms are applied to filter apparent point outliers for the first three categories, and a novel filtering approach is proposed for link outliers of the fourth category in urban areas using spatial reasoning rules without ancillary data. The proposed approach first measures specific geometric properties of links from trajectory databases and then evaluates the similarities of geometric measures among the links, following a set of spatial reasoning rules to determine link outliers. We tested this approach using taxi trajectory datasets for Beijing with a built-in sampling interval of 50 to 65 s. The results show that clustered links (27.14%) account for the majority of link outliers, followed by shortcut (6.53%), radial (3.91%), and drift (0.62%) outliers.

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 Integrity and Collaboration in Dynamic Sensor Networks

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2400 ◽  
Author(s):  
Steffen Schön ◽  
Claus Brenner ◽  
Hamza Alkhatib ◽  
Max Coenen ◽  
Hani Dbouk ◽  
...  
Keyword(s):  
Sensor Networks ◽  
Urban Areas ◽  
Research Training ◽  
Training Group ◽  
Autonomous Driving ◽  
Global Navigation Satellite Systems ◽  
Satellite Systems ◽  
Global Navigation Satellite ◽  
Map Data ◽  
Dynamic Sensor Networks

Global Navigation Satellite Systems (GNSS) deliver absolute position and velocity, as well as time information (P, V, T). However, in urban areas, the GNSS navigation performance is restricted due to signal obstructions and multipath. This is especially true for applications dealing with highly automatic or even autonomous driving. Subsequently, multi-sensor platforms including laser scanners and cameras, as well as map data are used to enhance the navigation performance, namely in accuracy, integrity, continuity and availability. Although well-established procedures for integrity monitoring exist for aircraft navigation, for sensors and fusion algorithms used in automotive navigation, these concepts are still lacking. The research training group i.c.sens, integrity and collaboration in dynamic sensor networks, aims to fill this gap and to contribute to relevant topics. This includes the definition of alternative integrity concepts for space and time based on set theory and interval mathematics, establishing new types of maps that report on the trustworthiness of the represented information, as well as taking advantage of collaboration by improved filters incorporating person and object tracking. In this paper, we describe our approach and summarize the preliminary results.

Enabling robust and accurate navigation for UAVs using real-time GNSS precise point positioning and IMU integration

2020 ◽  
Vol 125 (1283) ◽  
pp. 87-108
Author(s):  
C. Chi ◽  
X. Zhan ◽  
S. Wang ◽  
Y. Zhai
Keyword(s):  
Real Time ◽  
Precise Point Positioning ◽  
Three Dimensional ◽  
Coupled System ◽  
Measurement Unit ◽  
Satellite Geometry ◽  
Tightly Coupled ◽  
Point Positioning ◽  
Gnss Measurements ◽  
The One

ABSTRACTAccurate navigation is required in many Unmanned Aerial Vehicle (UAV) applications. In recent years, GNSS Precise Point Positioning (PPP) has been recognised as an efficient approach for providing precise positioning services. In contrast to the widely used Real-Time Kinematic (RTK), PPP is independent of reference stations, which greatly broadens its scope of application. However, the accuracy and reliability of PPP can be significantly decreased by poor GNSS satellite geometry and outage. In response, a real-time four-constellation GNSS PPP is applied to improve the geometry in this work, and PPP is tightly coupled with an Inertial Measurement Unit (IMU) to smooth the position and velocity output, thus improving the robustness of the navigation solution. Experimental flight tests are carried out using a UAV in an open-sky area, and GNSS-challenged environments are simulated. The results show that the four-constellation GNSS PPP/IMU integration reduces the Root-Mean-Square (RMS) Three-Dimensional (3D) positioning and velocity error by 76.4% and 67.1%, respectively, in open sky with respect to the one-GNSS PPP. Under scenarios where GNSS measurements are insufficient, the coupled system can still provide continuous solutions. Moreover, the coupled PPP/IMU system can also maintain the convergence of PPP during GNSS-challenged periods and can greatly shorten the re-convergence period of PPP when the UAV returns to the open sky.

Efficiency of Using GNSS-PPP for Digital Elevation Model (DEM) Production

2020 ◽  
Vol 55 (1) ◽  
pp. 17-28 ◽  
Author(s):  
Ashraf Abdallah ◽  
Amgad Saifeldin ◽  
Abdelhamid Abomariam ◽  
Reda Ali
Keyword(s):  
Digital Elevation Model ◽  
Cost Effective ◽  
Volume Estimation ◽  
Global Navigation Satellite Systems ◽  
Dual Frequency ◽  
Satellite Systems ◽  
Digital Elevation ◽  
Elevation Model ◽  
Kinematic Ppp ◽  
Global Navigation Satellite

AbstractIn the developing countries, cost-effective observation techniques are very important for earthwork estimation, map production, geographic information systems, and hydrographic surveying. One of the most cost-effective techniques is Precise Point Positioning (PPP); it is a Global Navigation Satellite Systems (GNSS) positioning technique to compute precise positions using only a single GNSS receiver. This study aims to evaluate the efficiency of using Global Positioning System (GPS) and GPS/ Globalnaya Navigatsionnaya Sputnikovaya Sistema (GLONASS) post-processed kinematic PPP solution for digital elevation model (DEM) production, which is used in earthwork estimation. For this purpose, a kinematic trajectory has been observed in New Aswan City in an open sky area using dual-frequency GNSS receivers. The results showed that, in case of using GPS/GLONASS PPP solution to estimate volumes, the error in earthwork volume estimation varies between 0.07% and 0.16% according to gridding level. On the other hand, the error in volume estimation from GPS PPP solution varies between 0.40% and 0.99%.

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