Extending the Applications and Improving the Efficiency of Positioning Through the Exploitation of New GNSS Signals
Lead Research Organisation:
University of Nottingham
Department Name: IESSG
Abstract
Abstracts are not currently available in GtR for all funded research. This is normally because the abstract was not required at the time of proposal submission, but may be because it included sensitive information such as personal details.
Organisations
- University of Nottingham (Lead Research Organisation)
- Airbus (United Kingdom) (Project Partner)
- Ordnance Survey (Project Partner)
- STMicroelectronics (United Kingdom) (Project Partner)
- Nottingham Scientific (United Kingdom) (Project Partner)
- Qinetiq (United Kingdom) (Project Partner)
- Thales (United Kingdom) (Project Partner)
- Air Semiconductor Ltd (Project Partner)
- Hexagon (United Kingdom) (Project Partner)
- Civil Aviation Authority (Project Partner)
Publications
Altti Jokinen (Author)
(2012)
Improving Fixed-ambiguity Precise Point Positioning (PPP) Convergence Time and Accuracy by using GLONASS
Altti Jokinen (Author)
(2012)
Fixed Ambiguity Precise Point Positioning (PPP) with FDE RAIM, In Proceedings of the PLANS 2012.
Elmas Z
(2011)
Higher order ionospheric effects in GNSS positioning in the European region
in Annales Geophysicae
Jokinen A
(2013)
GLONASS Aided GPS Ambiguity Fixed Precise Point Positioning
in Journal of Navigation
| Description | WP5 - Atmospheric Effects By slowing and bending the signals from the GNSS satellites, the atmosphere is one of the biggest sources of error in GNSS positioning. Atmospheric effects are conveniently separated into those caused by the upper atmosphere, the ionosphere, and those caused by the lower atmosphere, the troposphere. WP5 has tackled these two parts of the atmosphere separately, and has made significant progress in mitigating the effects and thereby improving the accuracy and robustness of GNSS positioning. For precise positioning applications, the best approach to dealing with the troposphere is to estimate the amount by which the signals have been delayed, as part of the positioning solution. This approach further allows the estimated delays to be used for weather forecasting. However, this approach makes no use of the accurate and up-to-date estimates of the state of the troposphere that are produced by, for instance, the UK Meteorological Office. WP5 has investigated, and demonstrated the benefit of, the use of precise ray tracing techniques to estimate tropospheric delay from the Met Office troposphere products. This improves convergence times in PPP. Furthermore, WP5 has demonstrated the potential improvement in the GNSS-based estimates of troposphere delays from the availability of multiple constellations of GNSS satellites. For the ionosphere, WP5 concentrated on the phenomenon of scintillation, in which rapid variations in ionospheric delay during periods of high ionospheric activity can cause receivers to lose lock on the GNSS signals. WP5 studied ionospheric scintillation models, and developed an end-to-end approach to simulate scintillation accurately using a Spirent GSS8000 simulator. WP6 - System Integration In each of its work packages the iNsight project has developed novel algorithms and approaches to processing signals from multi-constellation GNSS. WP6 developed the core data processing platform that enabled these algorithms to be implemented and tested in a consistent, reliable way, using state-of-the-art techniques. Interfaces have been developed and implemented to integrate with other groups within the project. For example, an interface allows measurements from high accuracy tropospheric models (WP5) to be used within the software. A close coupling between the positioning and integrity algorithms has also formed the basis for part of the integrity research (WP2). Based around a Kalman filter, the processing platform has implemented positioning using PPP with measurements from GPS and GLONASS and precise products such as those from the IGS. For GPS positioning, research has also been undertaken with products from CNES for fixing ambiguities with PPP. In addition to PPP research with real observations, the platform has also enabled the development and investigation of algorithms for multi-constellation positioning with simulated data. The Spirent GSS8000 simulator has been used to generate signals from modernised GPS and Galileo. Research has been undertaken that uses the software as a flexible platform for investigating algorithms such as linear combinations of observations to make full use of properties such as high accuracy code measurements. |
| Exploitation Route | WP5 - Atmospheric Effects The work on tropospheric delay estimation from Met Office products has the potential to improve the accuracy of real-time positioning, particularly for receivers using the Precise Point Positioning technique. It is envisaged that current real-time augmentation networks could be used to estimate localized improvements to the Met Office data for broadcast to local users. This technique would then allow receivers to apply this accurate external model to correct for tropospheric delay and therefore to achieve higher accuracy and quicker convergence in a PPP solution. WP6 - System Integration The research on multi-constellation processing remains a subject of current research and the optimum combination of signals from different systems is critical to obtaining the best results from GNSS receivers. This research therefore has potential to be exploited by receiver manufacturers. The iNsight processing filter uses a flexible plug-and-play approach to sensor integration and novel approaches for integrating GPS and low cost INS data to provide accurate roll, pitch and yaw information on a platform. This research has the potential to be used in many sectors, for instance in the automotive/motor sport sector where real-time velocity and attitude are required in a highly dynamic environment. WP5 - Atmospheric Effects In simple terms, please describe actual and/or potential ways this research can be put to use. The tropospheric work formed the basis of a proposal to ESA to develop new troposphere models, and is being further investigated with the use of a national network of continuously operating GNSS receivers. The findings of the ionospheric work have contributed to an FP7 project, 'Countering GNSS High Accuracy Applications Limitations Due To Ionospheric Disturbances In Brazil' (CALIBRA). In this project, the ionosphere scintillation mitigation methods are studied, based on the scintillation knowledge learnt from the iNsight project. WP6 - System Integration The data processing platform has been used extensively within the project, including as a testing ground for algorithms relating to tropospheric delay, Precise Point Positioning, and integrity. Due to its flexibility, it is regularly used within NGI as a processing tool for other research projects, including an EC FP7 project on using vision sensors to aid GNSS, and as a real-time processing engine for the NGI's 'foot tracker' pedestrian navigation system. |
| Sectors | Aerospace/ Defence and Marine,Agriculture, Food and Drink,Construction,Education,Environment,Leisure Activities, including Sports, Recreation and Tourism,Security and Diplomacy,Transport |
| URL | http://www.insight-gnss.org |