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.

ARMA Prediction of SBAS Ephemeris and Clock Corrections for Low Earth Orbiting Satellites

Abstract: For low earth orbit (LEO) satellite GPS receivers, space-based augmentation system (SBAS) ephemeris/clock corrections can be applied to improve positioning accuracy in real time. The SBAS correction is only available within its service area, and the prediction of the SBAS corrections during the outage period can extend the coverage area. Two time series forecasting models, autoregressive moving average (ARMA) and autoregressive (AR), are proposed to predict the corrections outside the service area. A simulated GPS satellite visibility condition is applied to the WAAS correction data, and the prediction accuracy degradation, along with the time, is investigated. Prediction results using the SBAS rate of change information are compared, and the ARMA method yields a better accuracy than the rate method. The error reductions of the ephemeris and clock by the ARMA method over the rate method are 37.8% and 38.5%, respectively. The AR method shows a slightly better orbit accuracy than the rate method, but its clock accuracy is even worse than the rate method. If the SBAS correction is sufficiently accurate comparing with the required ephemeris accuracy of a real-time navigation filter, then the predicted SBAS correction may improve orbit determination accuracy.

GBAS NSE model for CAT II/III autoland simulations

Abstract: Since many years, civil aviation has identified GNSS as an attractive mean to provide navigation services for every phase of flight due to its wide coverage area. However, GPS standalone cannot meet ICAO requirements in terms of accuracy, integrity, availability and continuity, particularly in the case of precision approaches. To achieve improved level of performance, different augmentation systems have been developed aiming at enhancing and monitoring the quality of the Signal-In-Space (SIS). In particular GBAS, for Ground Based Augmentation System, allows guarantying a very high level of performance in a given coverage area surrounding an airport for example.

Performance comparison of differential GNSS, EGNOS and SDCM in different user scenarios in Finland

Abstract: Positioning errors of stand-alone GNSS can be reduced with different real-time augmentation approaches. For many navigation and positioning applications, Satellite-Based Augmentation System (SBAS) and Differential code-based GNSS (DGNSS) can offer substantial improvement in the positioning accuracy. Finland is covered by EGNOS (European Geostationary Overlay Service) even though it is lying at the north-east margin of the coverage area. In addition to EGNOS, the neighboring SBAS system SDCM (System for Differential Corrections and Monitoring) has monitoring stations near Finland. In this work, the researchers at the Finnish Geospatial Research Institute (FGI) conducted some field experiments with mentioned SBASs and National Land Survey of Finland's (NLS) DGNSS service in order to find out reachable accuracies and rough estimates of availability in varying positioning conditions. Interest to SDCM grew due to its vicinity from Finland and also partly due to its ability to provide GLONASS corrections which EGNOS has not yet been able to offer.

Exploiting Standardized Metadata for GNSS SDR Remote Processing: A Case Study

Abstract: The proliferation of ad-hoc, highly customized, GNSS Software-defined radio (SDR) receivers and raw data collection systems is opening new opportunities for research focused on the analysis of new approaches in GNSS data processing. Especially when looking at the post-processing of GNSS signals for monitoring purposes, the availability of big-sized raw digital samples allows for the application of different algorithms and processing strategies on the same data-set, thus enabling valuable comparisons and proper tuning of the algorithms themselves. A side effect is that the huge quantity of GNSS data collections, grabbed in disparate scenarios and environmental conditions and distributed all around the world, is making hard to share this data between different research labs, thus limiting the possibility of conducting extensive analysis of relevant ionospheric phenomena affecting the quality to the GNSS signal. In this paper, the authors propose a novel methodology to deal with the processing and the management of this huge amount of data, and guarantee interoperability of different data collection and data processing systems leveraging on the adoption of a new emerging and open standard for GNSS metadata which is now under standardization by the ION GNSS SDR Metadata Standardization Working Group.

Transmitting GBAS messages via LDACS

Abstract: The Ground Based Augmentation System (GBAS)is a landing system for aircraft based on Global NavigationSatellite Systems (GNSS) It consists of a reference station at anairport that generates corrections and integrity parameters thatare transmitted to arriving aircraft The broadcast is currentlyaccomplished via a VHF data broadcast (VDB) In recent years itturned out that proper siting and frequency planning for theVDB is a challenging task in an operational environmentCoverage, as well as signal power issues, especially at large andcomplex airports have led to a number of considerations thathave to be taken into account when installing VDB transmissionantennas Furthermore, current GBAS only broadcastcorrections for the L1 frequency of GPS satellites Availabilityissues, mainly due to ionospheric effects in equatorial regions,however, drive the development of expanding GBAS from asingle frequency single constellation system towards a dualfrequency multi constellation architecture Transmittingadditional corrections and integrity parameters at the sameupdate rate is challenging due to the limited capacity of the VDBdata link Finally, transmission should offer the potential toprovide secure transmissions with an authenticated signal inorder to be robust also from a security perspective For all thesereasons it can be envisioned to provide the GBAS messages viaLDACS which is currently in the process of standardization Thiscould resolve the issues mentioned and thus support GBASimplementation in the future This paper provides an overview ofthe expected benefits mentioned above and provides a firstperformance estimation of GBAS over LDACS