Investigating the Benefits of Vector-Based GNSS Receivers for Autonomous Vehicles under Challenging Navigation Environments

There is a growing demand for robust and accurate positioning information for various applications, including the self-driving car industry. Such applications rely mainly on the Global Navigation Satellite System (GNSS), including the Global Positioning System (GPS). However, GPS positioning accuracy relies on several factors, such as satellite geometry, receiver architecture, and navigation environment, to name a few. In urban canyons in which there is a significant probability of signal blockage of one or more satellites and/or interference, the positioning accuracy of scalar-based GPS receivers drastically deteriorates. On the other hand, vector-based GPS receivers exhibit some immunity to momentary outages and interference. Therefore, it is becoming necessary to consider vector-based GPS receivers for several applications, especially safety-critical applications, including next-generation navigation technologies for autonomous vehicles. This paper investigates a vector-based receiver’s performance and compares it to its scalar counterpart in signal degraded conditions. The realistic simulation experiments in this paper are conducted on GPS L1 C/A signals generated using the SpirentTM simulation system to create a fully controlled environment to examine and validate the performance. The results show that the vector tracking system outperforms the scalar tracking in terms of position and velocity estimation accuracy in signal-degraded environments.

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

Sensors ◽

10.3390/s19133029 ◽

2019 ◽

Vol 19 (13) ◽

pp. 3029 ◽

Cited By ~ 2

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.

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Learning Geospatial Concepts as Part of a Non-Formal Education Robotics Experience

Advances in Early Childhood and K-12 Education - Robots in K-12 Education ◽

10.4018/978-1-4666-0182-6.ch014 ◽

2012 ◽

pp. 284-300 ◽

Cited By ~ 2

Author(s):

Viacheslav Adamchuk ◽

Bradley S. Barker ◽

Gwen Nugent ◽

Neal Grandgenett ◽

Megan Patent-Nygren ◽

...

Keyword(s):

Autonomous Vehicles ◽

Formal Education ◽

Satellite System ◽

Summer Camps ◽

Assessment Instruments ◽

Virtual Tools ◽

Youth Attitudes ◽

And Mathematics ◽

Global Navigation Satellite ◽

Technological World

In the increasingly modern and technological world, it has become common to use global navigation satellite system (GNSS), such as Global Positioning System (GPS), receivers, and Geographic Information Systems (GIS) in everyday life. GPS-equipped mobile devices and various Web services help users worldwide to determine their locations in real-time and to explore unfamiliar land areas using virtual tools. From the beginning, geospatial technologies have been driven by the need to make efficient use of natural resources. More recently, GPS-equipped autonomous vehicles and aircraft have been under development to facilitate technological processes, such as agricultural operations, transportation, or scouting, with limited or virtual human control. As outdoor robotics relies upon a number of principles related to science, technology, engineering, and mathematics (STEM), using such an instructional context for non-formal education has been promising. As a result, the Geospatial and Robotics Technologies for the 21st Century program discussed in this chapter integrates educational robotics and GPS/GIS technologies to provide educational experiences through summer camps, 4-H clubs, and afterschool programs. The project’s impact was assessed in terms of: a) youth learning of computer programming, mathematics, geospatial and engineering/robotics concepts as well as b) youth attitudes and motivation towards STEM-related disciplines. An increase in robotics, GPS, and GIS learning questionnaire scores and a stronger self-efficacy in relevant STEM areas have been found through a set of project-related assessment instruments.

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

Remote Sensing ◽

10.3390/rs11030311 ◽

2019 ◽

Vol 11 (3) ◽

pp. 311 ◽

Cited By ~ 3

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.

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A Joint Dual-Frequency GNSS/SINS Deep-Coupled Navigation System for Polar Navigation

Applied Sciences ◽

10.3390/app8112322 ◽

2018 ◽

Vol 8 (11) ◽

pp. 2322 ◽

Cited By ~ 2

Author(s):

Lin Zhao ◽

Mouyan Wu ◽

Jicheng Ding ◽

Yingyao Kang

Keyword(s):

Navigation System ◽

Density Ratio ◽

Satellite System ◽

The Arctic ◽

Observation Data ◽

Dual Frequency ◽

Vector Tracking ◽

Time Observation ◽

Global Navigation Satellite ◽

Navigation Accuracy

The strategic position of the polar area and its rich natural resources are becoming increasingly important, while the northeast and northwest passages through the Arctic are receiving much attention as glaciers continue to melt. The global navigation satellite system (GNSS) can provide real-time observation data for the polar areas, but may suffer low elevation problems of satellites, signals with poor carrier-power-to-noise-density ratio (C/N0), ionospheric scintillations, and dynamic requirements. In order to improve the navigation performance in polar areas, a deep-coupled navigation system with dual-frequency GNSS and a grid strapdown inertial navigation system (SINS) is proposed in the paper. The coverage and visibility of the GNSS constellation in polar areas are briefly reviewed firstly. Then, the joint dual-frequency vector tracking architecture of GNSS is designed with the aid of grid SINS information, which can optimize the tracking band, sharing tracking information to aid weak signal channels with strong signal channels and meet the dynamic requirement to improve the accuracy and robustness of the system. Besides this, the ionosphere-free combination of global positioning system (GPS) L1 C/A and L2 signals is used in the proposed system to further reduce ionospheric influence. Finally, the performance of the system is tested using a hardware simulator and semiphysical experiments. Experimental results indicate that the proposed system can obtain a better navigation accuracy and robust performance in polar areas.

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Monitoring Aircraft Position Using EGNOS Data for the SBAS APV Approach to the Landing Procedure

Sensors ◽

10.3390/s20071945 ◽

2020 ◽

Vol 20 (7) ◽

pp. 1945 ◽

Cited By ~ 3

Author(s):

Kamil Krasuski ◽

Damian Wierzbicki

Keyword(s):

Research Method ◽

Satellite System ◽

Civil Aviation ◽

International Civil Aviation Organization ◽

Positioning Accuracy ◽

Research Findings ◽

Global Navigation Satellite ◽

Service Data ◽

Computational Strategy ◽

Better Than

The aim of this paper is to present the problem of the implementation of the EGNOS (European Geostationary Navigation Overlay Service) data for the processing of aircraft position determination. The main aim of the research is to develop a new computational strategy which might improve the performance of the EGNOS system in aviation, based on navigation solutions of an aircraft position, using several GNSS (Global Navigation Satellite System) onboard receivers. The results of an experimental test conducted by the Cessna 172 at EPDE (European Poland Deblin) (ICAO (International Civil Aviation Organization) code, N51°33.07’/E21°53.52’) aerodrome in Dęblin are presented and discussed in this paper. Two GNSS navigation receivers with the EGNOS positioning function for monitoring changes in the parameters of the aircraft position in real time during the landing phase were installed onboard a Cessna 172. Based on obtained research findings, it was discovered that the positioning accuracy was not higher than 2.1 m, and the integrity of positioning did not exceed 19 m. Moreover, the availability parameter was found to equal 1 (or 100%); also, no intervals in the continuity of the operation of the EGNOS system were recorded. In the paper, the results of the air test from Dęblin were compared with the parameters of positioning quality from the air test conducted in Chełm (ICAO code: EPCD, N51°04’57.8” E23°26’15”). In the air test in Chełm, the obtained parameters of EGNOS quality positioning were: better than 4.9 m for accuracy, less than 35.5 m for integrity, 100% for availability, and no breaks in continuity. Based on the results of the air tests in Dęblin and Chełm, it was concluded that the parameters of the EGNOS positioning quality in aviation for the SBAS (Satellite Based Augmentation System) APV (Approach to Vertical guidance) procedure were satisfied in accordance with the ICAO (International Civil Aviation Organization) requirements. The presented research method can be utilized in the SBAS APV landing procedure in Polish aviation. In this paper, the results of PDOP (Position Dilution of Precision) are presented and compared to the two air tests in Dęblin and Chełm. The maximum results of PDOP amounted to 1.4 in the air test in Dęblin, whereas they equaled 4.0 in the air test in Chełm. The paper also shows how the EGNOS system improved the aircraft position in relation to the only GPS solution. In this context, the EGNOS system improved the aircraft position from about 78% to 95% for each ellipsoidal coordinate axis.

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Analysis of Deep Space Navigation Feasibility Based on Inter-Satellite Link Antenna of Satellite Navigation System

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.411-414.917 ◽

2013 ◽

Vol 411-414 ◽

pp. 917-921

Author(s):

Dong Hui Wang ◽

Wen Xiang Liu

Keyword(s):

Satellite System ◽

Geosynchronous Orbit ◽

Navigation Satellite ◽

Deep Space ◽

Positioning Accuracy ◽

Satellite Navigation System ◽

Space Navigation ◽

Simulation Results ◽

Global Navigation Satellite ◽

Navigation Method

There is no effectual navigation method to deep space aerocraft until now. Global Navigation Satellite System (GNSS) is a candidate. Its feasibility was analyzed according to the deep space geometry coverage characteristics. The antenna elevation was optimally designed to maximum the signal coverage performance in deep space. Simulation Results show that the best antenna elevation is 50-90 degrees. At the height of geosynchronous orbit, the average PDOP is 8.63, and at the height of lunar orbit, the positioning accuracy can only be achieved by km level.

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A Precise Weighting Approach with Application to Combined L1/B1 GPS/BeiDou Positioning

Journal of Navigation ◽

10.1017/s0373463314000320 ◽

2014 ◽

Vol 67 (5) ◽

pp. 911-925 ◽

Cited By ~ 18

Author(s):

Changsheng Cai ◽

Lin Pan ◽

Yang Gao

Keyword(s):

Time Window ◽

A Priori ◽

Estimation Method ◽

Satellite System ◽

Positioning Accuracy ◽

Satellite Systems ◽

Beidou System ◽

Component Estimation ◽

Navigation Service ◽

Global Navigation Satellite

The BeiDou system has been providing a regional navigation service since 27 December 2012. The Global Navigation Satellite System (GNSS) user community will benefit from combined Global Positioning System (GPS)/BeiDou positioning due to improved positioning accuracy, reliability and availability. But to achieve the best positioning solutions, precise weights of the GPS and BeiDou observations are important since this involves the processing of measurements from two different satellite systems with different quality. Currently, a priori variances are typically used to determine the weights of different types of observations. However, such an approach may not be precise since many un-modelled errors are not accounted for. The Helmert variance component estimation method is more appropriate in this case to determine the weights of GPS and BeiDou observations. This requires high redundant observations in order to obtain reliable solutions, which will be a concern in the case of insufficient numbers of visible satellites. To address this issue, a weighting approach is proposed by a combination of the Helmert method and a moving-window average filter. In this approach, the filter is applied to combine all epoch-by-epoch weight estimates within a time window. As a result, more precise and reliable weights for GPS and BeiDou observations can be obtained at every epoch. Both static and kinematic tests in open sky and under tree environments are conducted to assess the performance of the new weighting approach. The results indicate significantly improved positioning accuracy.

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AIOSAT - Autonomous Indoor & Outdoor Safety Tracking System

Annual of Navigation ◽

10.1515/aon-2019-0003 ◽

2019 ◽

Vol 26 (1) ◽

pp. 21-32

Author(s):

Iñigo Adin ◽

Paul Zabalegui ◽

Alejandro Perez ◽

Jaione Arrizabalaga ◽

Jon Goya ◽

...

Keyword(s):

Rural Areas ◽

Tracking System ◽

Dead Reckoning ◽

Wide Band ◽

Satellite System ◽

System Level ◽

Horizon 2020 ◽

Rescue Workers ◽

Global Navigation Satellite ◽

Map Data

Abstract Even though satellite-based positioning increases rescue workers’ safety and efficiency, signal availability, reliability, and accuracy are often poor during fire operations, due to terrain formation, natural and structural obstacles or even the conditions of the operation. In central Europe, the stakeholders report a strong necessity to complement the location for mixed indoor-outdoor and GNSS blocked scenarios. As such, location information often needs to be augmented. For that, European Global Navigation Satellite System Galileo could help by improving the availability of the satellites with different features. Moreover, a multi-sensored collaborative system could also take advantage of the rescue personnel who are already involved in firefighting and complement the input data for positioning. The Autonomous Indoor & Outdoor Safety Tracking System (AIOSAT) is a multinational project founded through the Horizon 2020 program, with seven partners from Spain, Netherlands and Belgium. It is reaching the first year of progress (out of 3) and the overarching objective of AIOSAT system is to advance beyond the state of the art in tracking rescue workers by creating a high availability and high integrity team positioning and tracking system. On the system level approach, this goal is achieved by fusing the GNSS, EDAS/EGNOS, pedestrian dead reckoning and ultra-wide band ranging information, possibly augmented with map data. The system should be able to work both inside buildings and rural areas, which are the test cases defined by the final users involved in the consortium and the advisory board panel of the project

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An overview of methodologies for real-time detection, characterisation and tracking of traveling ionospheric disturbances developed in the TechTIDE project

Journal of Space Weather and Space Climate ◽

10.1051/swsc/2020043 ◽

2020 ◽

Vol 10 ◽

pp. 42

Author(s):

Anna Belehaki ◽

Ioanna Tsagouri ◽

David Altadill ◽

Estefania Blanch ◽

Claudia Borries ◽

...

Keyword(s):

Real Time ◽

Large Scale ◽

Tracking System ◽

Warning System ◽

Satellite System ◽

Ionospheric Disturbances ◽

Time Activity ◽

Travelling Ionospheric Disturbances ◽

Additional Information ◽

Global Navigation Satellite

The main objective of the TechTIDE project (warning and mitigation technologies for travelling ionospheric disturbances effects) is the development of an identification and tracking system for travelling ionospheric disturbances (TIDs) which will issue warnings of electron density perturbations over large world regions. The TechTIDE project has put in operation a real-time warning system that provides the results of complementary TID detection methodologies and many potential drivers to help users assess the risks and develop mitigation techniques tailored to their applications. The TechTIDE methodologies are able to detect in real time activity caused by both large-scale and medium-scale TIDs and characterize background conditions and external drivers, as an additional information required by the users to assess the criticality of the ongoing disturbances in real time. TechTIDE methodologies are based on the exploitation of data collected in real time from Digisondes, Global Navigation Satellite System (GNSS) receivers and Continuous Doppler Sounding System (CDSS) networks. The results are obtained and provided to users in real time. The paper presents the achievements of the project and discusses the challenges faced in the development of the final TechTIDE warning system.

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Assessment of the Steering Precision of a Hydrographic USV along Sounding Profiles Using a High-Precision GNSS RTK Receiver Supported Autopilot

Energies ◽

10.3390/en13215637 ◽

2020 ◽

Vol 13 (21) ◽

pp. 5637

Author(s):

Łukasz Marchel ◽

Cezary Specht ◽

Mariusz Specht

Keyword(s):

High Precision ◽

Low Cost ◽

Path Following ◽

Satellite System ◽

Magnetic Compass ◽

Reference Station ◽

Positioning System ◽

Positioning Accuracy ◽

Unmanned Surface Vehicles ◽

Global Navigation Satellite

Unmanned Surface Vehicles (USV) are increasingly used to perform numerous tasks connected with measurements in inland waters and seas. One of such target applications is hydrography, where traditional (manned) bathymetric measurements are increasingly often realized by unmanned surface vehicles. This pertains especially to restricted or hardly navigable waters, in which execution of hydrographic surveys with the use of USVs requires precise maneuvering. Bathymetric measurements should be realized in a way that makes it possible to determine the waterbody’s depth as precisely as possible, and this requires high-precision in navigating along planned sounding profiles. This paper presents research that aimed to determine the accuracy of unmanned surface vehicle steering in autonomous mode (with a Proportional-Integral-Derivative (PID) controller) along planned hydrographic profiles. During the measurements, a high-precision Global Navigation Satellite System (GNSS) Real Time Kinematic (RTK) positioning system based on a GNSS reference station network (positioning accuracy: 1–2 cm, p = 0.95) and a magnetic compass with the stability of course maintenance of 1°–3° Root Mean Square (RMS) were used. For the purpose of evaluating the accuracy of the vessel’s path following along sounding profiles, the cross track error (XTE) measure, i.e., the distance between an USV’s position and the hydrographic profile, calculated transversely to the course, was proposed. The tests were compared with earlier measurements taken by other unmanned surface vehicles, which followed the exact same profiles with the use of much simpler and low-cost multi-GNSS receiver (positioning accuracy: 2–2.5 m or better, p = 0.50), supported with a Fluxgate magnetic compass with a high course measurement accuracy of 0.3° (p = 0.50 at 30 m/s). The research has shown that despite the considerable difference in the positioning accuracy of both devices and incomparably different costs of both solutions, the authors proved that the use of the GNSS RTK positioning system, as opposed to a multi-GNSS system supported with a Fluxgate magnetic compass, influences the precision of USV following sounding profiles to an insignificant extent.

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