Collaborative Navigation as a Solution for PNT Applications in GNSS Challenged Environments – Report on Field Trials of a Joint FIG / IAG Working Group
Allison KealyGuenther RetscherCharles TothAzmir Hasnur-RabiainVassilis GikasDorota A. Grejner‐BrzezinskaChris DanezisTerry Moore
27
Citation
4
Reference
20
Related Paper
Citation Trend
Abstract:
Abstract PNT stands for Positioning, Navigation, and Timing. Space-based PNT refers to the capabilities enabled by GNSS, and enhanced by Ground and Space-based Augmentation Systems (GBAS and SBAS), which provide position, velocity, and timing information to an unlimited number of users around the world, allowing every user to operate in the same reference system and timing standard. Such information has become increasingly critical to the security, safety, prosperity, and overall qualityof-life of many citizens. As a result, space-based PNT is now widely recognized as an essential element of the global information infrastructure. This paper discusses the importance of the availability and continuity of PNT information, whose application, scope and significance have exploded in the past 10–15 years. A paradigm shift in the navigation solution has been observed in recent years. It has been manifested by an evolution from traditional single sensor-based solutions, to multiple sensor-based solutions and ultimately to collaborative navigation and layered sensing, using non-traditional sensors and techniques – so called signals of opportunity. A joint working group under the auspices of the International Federation of Surveyors (FIG) and the International Association of Geodesy (IAG), entitled ‘Ubiquitous Positioning Systems’ investigated the use of Collaborative Positioning (CP) through several field trials over the past four years. In this paper, the concept of CP is discussed in detail and selected results of these experiments are presented. It is demonstrated here, that CP is a viable solution if a ‘network’ or ‘neighbourhood’ of users is to be positioned / navigated together, as it increases the accuracy, integrity, availability, and continuity of the PNT information for all users.Keywords:
GNSS augmentation
During the past few decades, the presence of global navigation satellite systems (GNSSs) such as GPS, GLONASS, Beidou and Galileo has facilitated positioning, navigation and timing (PNT) for various outdoor applications. With the rapid increase in the number of orbiting satellites per GNSS, enhancements in the satellite-based augmentation systems (SBASs) such as EGNOS and WAAS, as well as commissioning new GNSS constellations, the PNT capabilities are maximized to reach new frontiers. Additionally, the recent developments in precise point positioning (PPP) and real time kinematic (RTK) algorithms have provided more feasibility to carrier-phase precision positioning solutions up to the third-dimensional localization. With the rapid growth of internet of things (IoT) applications, seamless navigation becomes very crucial for numerous PNT dependent applications especially in sensitive fields such as safety and industrial applications. Throughout the years, GNSSs have maintained sufficiently acceptable performance in PNT, in RTK and PPP applications however GNSS experienced major challenges in some complicated signal environments. In many scenarios, GNSS signal suffers deterioration due to multipath fading and attenuation in densely obscured environments that comprise stout obstructions. Recently, there has been a growing demand e.g. in the autonomous-things domain in adopting reliable systems that accurately estimate position, velocity and time (PVT) observables. Such demand in many applications also facilitates the retrieval of information about the six degrees of freedom (6-DOF - x, y, z, roll, pitch, and heading) movements of the target anchors. Numerous modern applications are regarded as beneficiaries of precise PNT solutions such as the unmanned aerial vehicles (UAV), the automatic guided vehicles (AGV) and the intelligent transportation system (ITS). Hence, multi-sensor fusion technology has become very vital in seamless navigation systems owing to its complementary capabilities to GNSSs. Fusion-based positioning in multi-sensor technology comprises the use of multiple sensors measurements for further refinement in addition to the primary GNSS, which results in high precision and less erroneous localization. Inertial navigation systems (INSs) and their inertial measurement units (IMUs) are the most commonly used technologies for augmenting GNSS in multi-sensor integrated systems. In this article, we survey the most recent literature on multi-sensor GNSS technology for seamless navigation. We provide an overall perspective for the advantages, the challenges and the recent developments of the fusion-based GNSS navigation realm as well as analyze the gap between scientific advances and commercial offerings. INS/GNSS and IMU/GNSS systems have proven to be very reliable in GNSS-denied environments where satellite signal degradation is at its peak, that is why both integrated systems are very abundant in the relevant literature. In addition, the light detection and ranging (LiDAR) systems are widely adopted in the literature for its capability to provide 6-DOF to mobile vehicles and autonomous robots. LiDARs are very accurate systems however they are not suitable for low-cost positioning due to the expensive initial costs. Moreover, several other techniques from the radio frequency (RF) spectrum are utilized as multi-sensor systems such as cellular networks, WiFi, ultra-wideband (UWB) and Bluetooth. The cellular-based systems are very suitable for outdoor navigation applications while WiFi-based, UWB-based and Bluetooth-based systems are efficient in indoor positioning systems (IPS). However, to achieve reliable PVT estimations in multi-sensor GNSS navigation, optimal algorithms should be developed to mitigate the estimation errors resulting from non-line-of-sight (NLOS) GNSS situations. Examples of the most commonly used algorithms for trilateration-based positioning are Kalman filters, weighted least square (WLS), particle filters (PF) and many other hybrid algorithms by mixing one or more algorithms together. In this paper, the reviewed articles under study and comparison are presented by highlighting their motivation, the methodology of implementation, the modelling utilized and the performed experiments. Then they are assessed with respect to the published results focusing on achieved accuracy, robustness and overall implementation cost-benefits as performance metrics. Our summarizing survey assesses the most promising, highly ranked and recent articles that comprise insights into the future of GNSS technology with multi-sensor fusion technique.
Galileo (satellite navigation)
GLONASS
Real Time Kinematic
Precise Point Positioning
GNSS augmentation
Air navigation
Positioning technology
Cite
Citations (13)
Abstract Communication, positioning, navigation, and decision-making abilities have evolved into Positioning, Navigation, and Timing (PNT) intelligence during the long process of human migration and hence promoted human evolution. This article defines intelligence and smartness from the perspective of biological intelligence. New requirements as a result of the development of communication, navigation, time service, and decision making are identified in this study. The article points out that there are many radio PNT service methods, such as 5G, the new-generation high-speed communication networks and the low-latency and ubiquitous mobile communication networks as well as Global Navigation Satellite System (GNSS), but the integrated application is especially important in providing technical support for the adjustment and control of the physical world by intelligent sensing, cognition, decision-making, and precise coordination. The fusion of 5G and GNSS [including BeiDou Navigation Satellite System (BDS)] information with the corresponding equipment can be embedded into a machine to make it intelligent. Furthermore, the fused information of 5G and GNSS together with the environment information may extend human perception and physical world control ability in terms of time and space scale. It will help to develop critical information infrastructure in the age of intelligence, which will also extend the definition of artificial intelligence. Additionally, the “5G + BDS/GNSS” fusion path is analyzed explicitly herein in terms of realization methods, information processing, and new application services. On the whole, the application of “5G + BDS/GNSS + satellite-based communication” as a critical infrastructure for land, sea, air, space and network spatiotemporal control rights is proposed.
GNSS augmentation
Cite
Citations (46)
Positioning, Navigation, and Timing (PNT) services are key enablers of both essential safety and security applications and economically beneficial capacity and efficiency applications worldwide. Whether users are ground-based, sea-based or in the air, their primary/go-to source of PNT has become a Global Navigation Satellites System (GNSS), with the US Global Positioning System (GPS) being the most widely used. Starting in 2001, with the publishing of the landmark Volpe Transportation Systems Center’s GPS Vulnerability Report and leading up to the Department of Homeland Security sponsored GPS Interference Testing in 2012, the world has became much more aware of the vulnerability of GNSS-based services – especially in 2011, as the result of significant interest in using the spectrum directly adjacent to GPS for mobile communications services. This was an important wake up call to the world. But while users of GNSS positioning and navigation services are usually at least cognizant of the source of their services, many users of GPS precise time and frequency are oblivious to both the source of these services and their inherent vulnerability. In fact many time and frequency users are not even aware of how GNSS-provided time is crucial to their operations. The Federal Aviation Administration (FAA) has initiated an Alternate Position, Navigation, and Timing (APNT) program to research various alternative strategies. These strategies are necessary to ensure a safe, secure, and effective transition of the US National Airspace System (NAS) to the Next Generation Air Transportation System (NextGen). While discussing some of the position and navigation aspects of this program, this paper concentrates on the need for a robust time and frequency alternative to GNSS that will support aviation and have the potential to provide robust precise time and frequency services to other user communities. Alternatives strategies to be explored include use of existing NAS ground-based navigation aids, high power ground waves, antenna technologies, and alternative satellite constellations.
Vulnerability
GNSS augmentation
Cite
Citations (8)
This article focuses on position, navigation, and time (PNT) applications for smart city mobility services, in particular those applicable to highly automated vehicles (HAVs). We examine precise timing applications that are being experimented from a PNT perspective. Aspects discussed include precision timing requirements for HAV, whether or not these can be met by evolving GNSS services or onboard systems, and if not, what PNT instances, if any, can be economically deployed to enable the levels of autonomy that are currently expected.
Position (finance)
Cite
Citations (24)
Global Positioning System (GPS) has been widely used worldwide for a variety of applications such as air, land and sea. The GPS and the Russian GLONASS are the only fully operational Global Navigation Satellite System (GNSS). Due to its several advantages, such as simplicity of use, successful implementation and global availability, this has been considered as the cornerstone of positioning in navigation system applications for the people who are visually impaired. However, due to standalone single frequency service, the positioning performance has not been sufficient for some accuracy and precision demanding applications. The problems of obtaining high accuracy real time positions in the field have led the navigation community to develop a GNSS augmentation system. However, several questions have been raised with this new development, such as how good the new method is? During any satellite configuration, would it be able to provide the accuracy at the same level? In a reliable way, would it be able to replace conventional GPS method? In this paper, a detailed review of all necessary understandings concerning GNSS and with a focal point on the GPS, GLONASS, Galileo, Beidou and GNSS augmentation systems positioning performance, is provided. The enormous demand to further improve positioning, navigation, and timing capabilities for both civil and military users on existing GNSS systems has directed efforts to modernise the GPS and GLONASS system and introduce new systems such as Galileo navigation system.
GLONASS
Galileo (satellite navigation)
GNSS augmentation
Real Time Kinematic
Air navigation
Precise Point Positioning
Navigation System
Cite
Citations (0)
Spectral Compression Positioning™ (SCP) is an innovative method for deriving positioning, navigation, and timing (PNT) information from Signals of Opportunity (SoOps). The method enables precise PNT in GNSS obstructed environments providing expanded coverage, reliability, and accuracy. This paper introduces the core principles of SCP-based PNT and explores both autonomous and network-based implementation architectures. Providing precise, cost-effective, and autonomous positioning information for navigating indoors or in GPS obstructed environments is a technical challenge that remains largely unsolved. Advances in hybrid Wi-Fi/A-GPS positioning and inertial technologies have yet to deliver meter-level accuracy without the need for custom infrastructure or extensive RF fingerprinting. SCP technology offers a unique alternative approach to current RF-based positioning techniques that readily exploits terrestrial and orbital Signals of Opportunity without the requirement for purpose built infrastructure or a priori knowledge of the signal source location and clock states.
Cite
Citations (9)
Cite
Citations (0)
Vehicle to infrastructure collaboration is an important component of unmanned cluster collaborative positioning system. With the continuous improvement of mission target, the requirements for the accuracy and fault tolerance of vehicle collaborative positioning are getting higher. However, under the environment of crowed building groups that the GNSS signals are blocked, which affects the accuracy and performance of navigation and positioning. In this paper, the UWB is introduced to collaborate with the INS/GNSS integrated navigation system, and a collaboration strategy is designed to improve both the navigation performance and the efficiency of system resource. Simulation results show that the proposed INS/GNSS/UWB collaboration system improves the positioning precision significantly in the situation of bad observation in crowed environments.
Component (thermodynamics)
Navigation System
GNSS augmentation
Air navigation
Cite
Citations (4)
The implementation of e-Navigation is underway. This concept for the harmonization and integration of maritime information systems onboard and ashore is likely to become a reality over the next five years, leading to fewer accidents, safer more efficient navigation and protection of the environment. Almost every solution provided under the e-Navigation initiative depends on an electronic position input. At present that input comes almost exclusively from GPS. Given the vulnerability of GPS (and other Global Navigation Satellite Systems - GNSS) to disruption, that situation is not sustainable. Various options for GNSS backup are being explored. This paper looks at some of the alternatives that have been tested and demonstrated and assesses their potential for completing GNSS to provide resilient PNT. eLoran is the most advanced of the alternatives and the only one likely to be ready in time for the implementation of e-Navigation: eLoran has reached Initial Operational Capability in the UK. This paper reports the results of demonstrations carried out there, describes the equipment being evaluated and sets out the steps towards Full Operational Capability.
The status of Loran in other parts of the World is reported and some initiatives proposed that could make it a realistic component of a World Wide Radio Navigation System, providing Resilient PNT for all applications.
SAFER
Harmonization
Galileo (satellite navigation)
Component (thermodynamics)
Air navigation
Vulnerability
Cite
Citations (1)
GNSS augmentation
Cite
Citations (0)