scispace - formally typeset
Search or ask a question
Topic

GNSS augmentation

About: GNSS augmentation is a research topic. Over the lifetime, 2478 publications have been published within this topic receiving 28513 citations. The topic is also known as: SBAS & Satellite Based Augmentation System.


Papers
More filters
29 Sep 2006
TL;DR: The purpose of this work is to investigate which Vertical Protection Level (VPL) values could be achieved with RAIM under conservative failure assumptions and to revise the RAIM algorithm and corresponding threat model.
Abstract: With the much anticipated deployment of Galileo, a new partner will rise on the sky of Global Navigation Satellite Systems (GNSS). Equally anticipated is the launch of the modernized block III GPS satellites, which will provide numerous enhancements to the existing system. It is expected that both Galileo and the modernized GPS will become fully operational within the next 10 years. As a consequence, efforts have been initiated at the global level in order to contrive ways in which to gain the full benefits of having two independent multifrequency systems available to the user. One of the hard problems that stand-alone GPS has been trying to address over the years is that of measurement integrity. Providing guidance during the landing approach phase of aircraft flight is one of the most challenging applications for satellite-based navigation because both high accuracy and user safety are required during the procedure. By combining two frequencies, users will be able to remove the ionospheric delay, which is currently the largest error, and thus increase the positioning accuracy by more than 50%. This reduction in nominal error bounds together with the presence of a larger number of satellites is going to increase the robustness against satellite failures or hazardous pseudorange errors. Previous studies [Ene et al. 2006] suggest that, using Receiver Autonomous Integrity Monitoring (RAIM), it might be possible to provide a 35m Vertical Alert Limit (VAL) worldwide, with a bound on the maximum error and without the need for additional augmentation, even in the event of one satellite failure, one constellation failure or a multiple satellite failure. The purpose of this work is to investigate which Vertical Protection Level (VPL) values could be achieved with RAIM under conservative failure assumptions. Both the RAIM algorithm and the corresponding threat model presented in the previous paper [Ene et al. 2006] have been revised. The previously defined threat model is refined to include measurement biases, and the study on degraded operation modes is also extended to include partial GPS and Galileo constellations and to appreciate the impact of critical satellites. It was found that an unaided dual Galileo-GPS constellation yielded VPL values under 20m for nominal operation conditions, and that moderate biases or degenerate constellations can increase the VPL up to around 35m. These protection levels will likely enable APV-II landings at all runway ends in the world without the need for a SBAS or GBAS.

13 citations

Proceedings ArticleDOI
03 Oct 2004
TL;DR: This paper is to present how a GNSS/INS integrated system offers the accuracy and quality assurance required in remote services.
Abstract: Nowadays, one of the most important applications of the navigation systems is the remote services. Applications such as the electronic-fee-collection, truck fleet control or antitheft devices imply millions of users through the roads of the whole world. Particularly in Europe, the development of the GALILEO system and the efforts of the European Parliament in prioritizing the toll collecting systems based on GNSS and cellular networks (GNSS/CN), enlarge highly the European market of potential users. In that million users market, no particular exceptions can be treated by a realistic solution. Most of the actual navigation systems rely mainly on the satellite navigation. Problems such as the deficit of precision, the lack of coverage or the service interruptions due to disturbances on the satellite network arouse the implementation of a more reliable solution combining GNSS and autonomous navigation systems. This paper is to present how a GNSS/INS integrated system offers the accuracy and quality assurance required in remote services. Both practical and theoretical researches about the possibilities of a single GPS receiver, the EGNOS-SISNeT/SBAS position correction improvements, the incoming GALILEO-GPS constellation and the use of a multisensor GNSS/INS integrated solution as a reliable navigation system for remote services applications are presented.

13 citations

Patent
02 Mar 2012
TL;DR: The invention provides a high precision single point positioning system of a single frequency global positioning system (GPS) and a method, which belong to the technical field of GPS positioning, which have the advantages of being simple in data collection and high in precision.
Abstract: The invention provides a high precision single point positioning system of a single frequency global positioning system (GPS) and a method, which belong to the technical field of GPS positioning. The positioning system is provided with a single frequency GPS receiver which finishes the processing of a GPS baseband signal, tracing of a GPS signal and pressure-volume-temperature (PVT) resolving and provides required GPS observation data and various error correcting information for a precision single point positioning solving module. The receiving of various correction data and loading of information of international GPS service (IGS) precise ephemeris, clock error, ionospheric delay and the like are finished by wireless communication module general packet radio service (GPRS) through wireless networks. The wireless communication module GPRS performs ionospheric delay error correction, satellite clock error correction and satellite track error correction, and utilizes IGS network data to finish precision single point positioning processing. An ARM core plate receives various observation data, satellite-based augmentation system (SBAS) observation data and various correction data of the wireless communication module and performs automatic processing computing of precision single point positioning algorithm. The single frequency GPS high precision single point positioning system and the method have the advantages of being simple in data collection and high in precision, and the feasibility and flexibility of the precision positioning are improved.

12 citations

24 Sep 2004
TL;DR: A range of ionospheric issues that an SBAS must consider if it is to comply with the ICAO SARPs are surveyed, including potential routes in bounding or mitigating the effect of these highly irregular periods of ionsospheric activity by considering the approach WAAS has employed.
Abstract: The ionosphere contributes the largest and most unpredictable error to single frequency GPS users’ range measurements. The goal of a Space-Based Augmentation System (SBAS) in mitigating these ionospheric errors is two-fold. First, the SBAS broadcasts error corrections to its users for improved positioning accuracy. Moreover, the SBAS provides a service that GPS alone cannot: ensuring position estimate integrity, which is crucial to safety-of-life applications. The International Civil Aviation Organization (ICAO) has adopted a set of Standards and Recommended Practices (SARPs) for SBASs being developed worldwide. The SARPs are based on the Minimum Operational Performance Standards (MOPS) of the Wide Area Augmentation System (WAAS) currently operational in the United States. This paper surveys a range of ionospheric issues that an SBAS must consider if it is to comply with the ICAO SARPs. By examining observed ionospheric phenomena at a high level in a visually intuitive way, the author hopes to provide some insight as to why the SARPs are developed as they are and what additional issues are introduced by the constraints of the SARPs. This paper makes use of the following data: “supertruth” data collected from the WAAS network of receivers during several ionospheric storms as well as a nominal period for comparison; raw data from an individual WAAS network receiver during the 29-31 October 2003 ionospheric storm; and data from the same storm collected from nearly 400 stations in the Continuously Operating Reference Stations (CORS) and International GPS Service (IGS) networks and processed by the Jet Propulsion Laboratory (JPL). With these data sets the author illustrates the large absolute values of total electron content (TEC), to which GPS range errors are proportional, that may be seen during ionospheric storms. Large spatial and temporal gradients that have been observed are also shown. We discuss potential routes in bounding or mitigating the effect of these highly irregular periods of ionospheric activity by considering the approach WAAS has employed. In addition to bounding dangerous behavior that is not predicted by the SBAS choice of ionospheric model, the SBAS must also bound estimation and interpolation errors that exist both during nominal and stormy conditions. Such errors are introduced by modeling the ionosphere as a two-dimensional, infinitely thin shell. This error arises from the loss of altitudinal information in the collapse of the three spatial dimensions of the true ionosphere into a two-dimensional surface representation that can be easily broadcast. Finally, with an ionospheric model based on measurement and estimation of the real-time ionosphere, the SBAS runs a risk of undersampling the ionosphere over a geographic region for which it is providing service, as will be illustrated. When high spatial and temporal gradients are also highly localized, it is possible for them to remain undetected by the SBAS. For this reason bounding possible errors due to undersampling is crucial.

12 citations

Journal ArticleDOI
TL;DR: In this article , the authors used the probability integral model to process deformation data obtained from an Unmanned Aerial Vehicle (UAV), Differential InSAR (DInSAR), and Small Baseline Subset InSARS (SBAS-InSARS) to obtain the complete deformation field.
Abstract: For the accurate and high-precision measurement of the deformation field in mining areas using different data sources, the probability integral model was used to process deformation data obtained from an Unmanned Aerial Vehicle (UAV), Differential InSAR (DInSAR), and Small Baseline Subset InSAR (SBAS-InSAR) to obtain the complete deformation field. The SBAS-InSAR, DInSAR, and UAV can be used to obtain small-scale, mesoscale, and large-scale deformations, respectively. The three types of data were all superimposed by the Kriging interpolation, and the deformation field was integrated using the probability integral model to obtain the complete high-precision deformation field with complete time series in the study area. The study area was in the WangJiata mine in Western China, where mining was carried out from 12 July 2018 to 25 October 2018, on the 2S201 working face. The first observation was made in June 2018, and steady-state observations were made in April 2019, totaling four UAV observations. During this period, the Canadian Earth Observation Satellite of Radarsat-2 (R2) was used to take 10 SAR images, the surface subsidence mapping was undertaken using DInSAR and SBAS-InSAR techniques, and the complete deformation field of the working face during the 106-day mining period was obtained by using the UAV technique. The results showed that the subsidence basin gradually expanded along the mining direction as the working face advanced. When the mining advance was greater than 1.2–1.4 times the coal seam burial depth, the supercritical conditions were reached, and the maximum subsidence stabilized at the value of 2.780 m. The subsidence rate was basically maintained at 0.25 m/d. Finally, the accuracy of the method was tested by the Global Navigation Satellite System (GNSS) data, and the medium error of the strike was 0.103 m. A new method is reached by the fusion of active and passive remote sensing data to construct efficient, complete and high precision time-series subsidence basins with high precision.

12 citations


Network Information
Related Topics (5)
Radar
91.6K papers, 1M citations
82% related
Object detection
46.1K papers, 1.3M citations
73% related
Communications system
88.1K papers, 1M citations
72% related
Wireless sensor network
142K papers, 2.4M citations
72% related
Wireless
133.4K papers, 1.9M citations
72% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023122
2022266
202144
202062
201956
201851