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 published on a yearly basis
Papers
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01 Nov 2010TL;DR: A new implementation of multi-mode GNSS signal simulator controlled by computer with strong advantages of parallel processing ability of FPGA and complex calculation ability of computers is proposed.
Abstract: In order to meet the demands of complicated calculation and high real-time performance, a new implementation of multi-mode GNSS signal simulator controlled by computer is proposed. Navigation control parameters are calculated by computers. Then, they are sent to satellite signal generator via network interface to control signal generation. This combination displays strong advantages of parallel processing ability of FPGA and complex calculation ability of computers. The system is verified with respect to the output signals and positioning solutions and is successfully applied in the research of satellite navigation receiver.
9 citations
28 Sep 2007
TL;DR: The proposed framework is designed to be a comprehensive, server-based, and thin-client platform that provides end-users with “out-of-the-box” services and adopts upto-date database technologies and web technologies that enable servers to perform data management and spatial analysis while end- users are able to syndicate data and create their own business models.
Abstract: The diversification of Global Navigation Satellite Systems (e.g. the current and modernized GPS, the revitalized GLONASS, the planned Galileo and Compass), is an opportunity for engineers, surveyors and geodesists because of expected improvements in positioning accuracy, operational flexibility, redundancy, and quality assurance. Recent research activities include new algorithms for multiple frequency ambiguity resolution, software-based receivers for re-configurability, network corrections for utilising redundancy, reversed real-time kinematic schemes for quality/accuracy improvement, and a wide range of rover-side applications. This paper discusses the integration of these “pieces” of work into a new framework and facilitates information and communication technologies in order to derive benefits from network infrastructure such as continuously operating reference stations and local/regional GPS networks. Operational models are proposed for precise point positioning and real-time kinematic services including “near real-time” applications, which require an optimal design to balance the computational overhead with data communication latency. The proposed framework is designed to be a comprehensive, server-based, and thin-client platform. It provides end-users with “out-of-the-box” services. Endusers should be able to obtain extensive GNSS capabilities and high productivity without conventional constraints such as an expensive set of receivers, proprietary data formats, user-installed carrier phase processing software, incomplete interoperability, limited communication links, etc. The framework also adopts upto-date database technologies and web technologies that enable servers to perform data management and spatial analysis, while end-users are able to syndicate data and create their own business models. The framework has been applied to SydNET, a network of continuously operating reference stations located in Sydney, Australia. It is expected that the new framework will be versatile enough to cope with a diverse range of user performance requirements and the operational requirements for communications and positioning computations.
9 citations
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29 Mar 2007
TL;DR: The GNSS for RAIL project as discussed by the authors is an FP6 project aiming to address the use of GNSS in all rail applications, however, the number of railway applications where GNSS could be used is very large and so the focus of the project is on Safety-Critical applications and specifically on ETCS (European Train Control System), although other applications (like Asset Management, etc) are also investigated.
Abstract: GRAIL is an FP6 project initially managed by the Galileo Joint Undertaking (GJU), but this year being managed by the GNSS Supervisory Authority (GSA) that has taken over from the GJU The title of the project, GNSS for RAIL, addresses the use of GNSS in all rail applications However, the number of railway applications where GNSS could be used is very large and so the focus of the project is on Safety-Critical applications and specifically on ETCS (European Train Control System), although other applications (like Asset Management, etc) are also investigated The first ETCS application to be addressed in the project is the use of GNSS in enhanced odometry In this configuration, GNSS-based location is used as substitute or complement to the current odometry sensors (tachometers, INS, Doppler Radar etc) It can, therefore, remain internal to the ETCS (as a part of the Odometry Macrofunction) In this configuration the GNSS system is composed only of a GNSS receiver, augmented, if needed, by local elements to achieve the required performances (in safety, for example) The expected improvements of this approach for ETCS are the overall improvement of Train Location accuracy and a reduction in safety margins and tolerances The presentation will address the common specifications agreed in GRAIL by all signalling suppliers and under review by ETCS rail operators, as well as the future trials in Spain
9 citations
19 Sep 2008
TL;DR: In this article, the authors compared the performance of GPS and GNSS solutions in constrained and in particular urban environments, where there are less satellites in visibility and multi-path effects.
Abstract: GPS solution in based on the synchronization of emitting
satellites to the same time which is maintained in the GPS
system. Glonass, Galileo… have their own time. So the
differences between the different times of systems shall be
known to synchronize all pseudo-ranges measurements in
the receiver to a common time, and then to calculate a
GNSS global position.
Considering the GPS and Galileo possible combinations,
there will be two main solutions to get the GPS to Galileo
Time Offset (GGTO) : GGTO will be broadcast by both
constellations, or it can be estimated in the receiver. In
unconstrained environments, with typically 8 to 10
satellites from each constellation, those two solutions will
have similar performances (4 or 5 unknowns versus nearly
20 measurements).
The article focuses on constrained and in particular urban
environnement performances for both solutions, where
there are less satellites in visibility and multi-path effects.
Simulations with a realistic 3D model of the city of
Toulouse in France, have been done using a special
software Ergospace® to evaluate the difference between
the two solutions. A third solution using the “best”
solution according to the number of satellites received and
DOPs criteria has been also analysed.
As shown from simulations, in the different constrained
environments considered, positioning errors are mainly
due to poor visibility and multi-path effects, and
horizontal errors are typically between a few meters to
nearly 50 meters.
Main results are the following:
• There are no big differences in simulated positioning
variances using Broadcast GGTO or the receiverestimated
GGTO, even in constrained environment.
• Positioning performance sensitivity to GGTO
accuracy is low, in particular in urban environment.
As Broadcast GGTO error is likely to be a few
nanoseconds, it can be directly used, in particular in
urban environment, it could also be used for integrity
checking.
It shall be also noted that using a 5th unknown for GGTO
will cope with GGTO residual error, inter-system biases,
or SBAS corrections and will generally lower the
residuals.
9 citations
23 Sep 2011
TL;DR: Two multi-pole complex adaptive Infinite Impulse Response (IIR) and Finite Impulse response (FIR) notch filtering techniques have been implemented in a GNSS vector-based software receiver to mitigate Continuous Wave Interference (CWI) and swept interference.
Abstract: Vector-based tracking has gained much attention due to its superior code phase and carrier Doppler tracking performance compared to scalar tracking architecture under Radio Frequency (RF) interference. However, the robustness of vector-based tracking still cannot satisfy the requirements for many applications under strong RF interference conditions. Moreover, because the pseudorange and pseudorange-rate based navigation solution feedback in vector-based tracking only controls the code phase and carrier Doppler tracking, individual carrier phase tracking is still required. Therefore, it is desirable to improve the carrier phase tracking performance in vector-based receivers under strong interference. In this paper, two multi-pole complex adaptive Infinite Impulse Response (IIR) and Finite Impulse Response (FIR) notch filtering techniques have been implemented in a GNSS vector-based software receiver to mitigate Continuous Wave Interference (CWI) and swept interference. The main focus of this paper is the implementation and the performance comparison of these two notch filters in a GNSS vector-based software receiver by processing simulated GNSS signals with CWI and swept interference generated from a hardware simulator.
9 citations