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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.


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Patent
12 Mar 2012
TL;DR: In this paper, an approach and methods for providing fine timing assistance to global navigation satellite systems (GNSS) via wireless local area network (WLAN) is described. But the method is not suitable for wireless networks.
Abstract: Apparatus and methods are disclosed for providing fine timing assistance to global navigation satellite systems (GNSS) via wireless local area network (WLAN). In one embodiment, a method (300) for synchronizing a global navigation satellite system (GNSS) receiver includes receiving (308), by a wireless device, via a wireless local area network (WLAN), fine time assistance information transmitted by an assisting device connected to the WLAN. A time value of a GNSS clock of the wireless device is adjusted (312) based on the fine time assistance information. Based on the adjusted time value, GNSS codes of a GNSS positioning signal are acquired (314) by the wireless device.

19 citations

24 Sep 2004
TL;DR: In this paper, the effects of the troposphere on satellite-based differential augmentations for aircraft precision approach and landing applications are analyzed and compared, and the potential for erroneous tropo corrections is illustrated by comparing models over a range of input parameters, including temperature, pressure, relative humidity, refractivity index (and uncertainty), as well as the tropospheric scale height.
Abstract: This paper provides an in-depth analysis of the effects of the troposphere on satellite-based differential augmentations for aircraft precision approach and landing applications. The results of this effort are applicable to both the Space and Ground Based Augmentations Systems (GBAS/SBAS), including the Wide and Local Area Augmentation Systems (WAAS/LAAS) using GPS and/or Galileo. It is widely recognized that the dominant, non-common error sources in differential GNSS for aviation are noise, multipath, the ionosphere, and the troposphere. Of these errors, the troposphere is perhaps the least studied and least quantified error source within the aviation community. To fill this information void, the current models used to estimate the tropospheric corrections in the WAAS and LAAS Category I aircraft precision system are analyzed and compared. The potential for erroneous tropo corrections is illustrated by comparing models over a range of input parameters, including temperature, pressure, relative humidity, refractivity index (and uncertainty), as well as the tropospheric scale height. While the LAAS troposphere model primarily address the differential vertical tropospheric gradient between the LAAS ground station and approaching aircraft as a function of the altitude difference, it is also important to account for the tropo errors due to lateral separation. For operations at large airports, the LAAS ground station may be separated by distances up to three miles from the approach-end of the runway. At this distance during clear, stable weather conditions, errors due to lateral separation are often considered negligible. However, under severe weather conditions, localized weather behavior may cause the differential tropospheric corrections to exceed their budgeted values, especially for low-elevation satellites. Furthermore, the LAAS tropo corrections must be valid over the entire 23-nautical mile LAAS service volume to ensure safe terminal-area operations. Clearly, over this distance, lateral tropo gradients may become significant. Analogous to the strict error budgets developed for multipath and ionospheric errors, tropospheric errors must also be carefully considered and properly accounted for. To address this issue, several case studies are shown using weather information obtained from the Ohio University Scalia Laboratory for Atmospheric Analysis. The results of this research are of particular importance to WAAS and LAAS development because, if and when the aviation community adopts a multi-frequency, multiconstellation architecture to meet the most stringent requirements of Category II/III aircraft precision approach and landing operations, tropospheric anomalies will remain as a key error source that must be well understood and modeled in this aviation safety-of-life application.

19 citations

Journal ArticleDOI
24 Dec 2014-Sensors
TL;DR: Several loosely- and tightly-coupled approaches are developed and combined with pseudolite proximity and receiver signal strength (RSS)-based positioning and demonstrate that the methods developed are effective techniques for integrating heterogeneous measurements from different sources, such as asynchronous pseudolites and GNSS.
Abstract: global navigation satellite system (GNSS) receivers are usually unable to achieve satisfactory performance in difficult environments, such as open-pit mines, urban canyons and indoors. Pseudolites have the potential to extend GNSS usage and significantly improve receiver performance in such environments by providing additional navigation signals. This also applies to asynchronous pseudolite systems, where different pseudolites operate in an independent way. Asynchronous pseudolite systems require, however, dedicated strategies in order to properly integrate GNSS and pseudolite measurements. In this paper, several asynchronous pseudolite/GNSS integration strategies are considered: loosely- and tightly-coupled approaches are developed and combined with pseudolite proximity and receiver signal strength (RSS)-based positioning. The performance of the approaches proposed has been tested in different scenarios, including static and kinematic conditions. The tests performed demonstrate that the methods developed are effective techniques for integrating heterogeneous measurements from different sources, such as asynchronous pseudolites and GNSS.

19 citations

Journal ArticleDOI
TL;DR: Results show that the method introduced could be a suitable method to detect GNSS clock events and some results obtained by monitoring actual GNSS satellite clocks are presented.
Abstract: This paper introduces a method of detecting atomic clock anomalies for Global Navigation Satellites System (GNSS) satellites in real-time mode and presents some results obtained by monitoring actual GNSS satellite clocks. The method employs a Kalman filter formulation which facilitates the real-time processing of GNSS carrier-phase measurements. Judgment regarding clock anomalies is made using the prediction interval approach and actual distribution of predicted phase and frequency error is replaced by overbounding Gaussian distribution. Results show that the method could be a suitable method to detect GNSS clock events.

19 citations

Journal ArticleDOI
TL;DR: In this paper, the authors presented an assessment of the impact that the integration of Global Navigation Satellite Systems (GNSS) with Inertial Navigation Systems (INS) would have on the aids to navigation (AtoN) services currently provided, and those to be provided in the future.
Abstract: A version of this paper was presented at ENC-GNSS 2007, Geneva. Its reproduction was kindly authorised by the ENC-GNSS 07 Paper Selection Committee.The General Lighthouse Authorities of the UK & Ireland commissioned an assessment of the impact that the integration of Global Navigation Satellite Systems (GNSS) with Inertial Navigation Systems (INS) would have on the aids to navigation (AtoN) services currently provided, and those to be provided in the future. There is concern about the vulnerability of GNSS, and the provision of complementary and backup systems is seen to be of great importance. The integration of INS could provide an independent and self-contained navigation system, for a limited time period, invulnerable to external intentional or unintentional interference, or the influences of changes in national policies. The study included an analysis of the potential use of GNSS-INS in three of the four phases of a vessel's voyage: coastal, port approach and docking. The project consisted of a technology assessment, looking at the different inertial technologies that might be suitable for each phase. This was followed by a technology proving stage, evaluating suitable equipment using simulation and field trials to prove that the claimed performance could be achieved in practice. The final stage of the project was to assess the effects of the availability of such systems on existing and planned aids to navigation services.

19 citations


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Performance
Metrics
No. of papers in the topic in previous years
YearPapers
2023122
2022266
202144
202062
201956
201851