This, and the following three papers, were first presented at GNSS 2000, the Third European Symposium on Global Navigation Satellite Systems held in Edinburgh, Scotland from 1st to 4th May 2000.

GNSS, or more specifically, Satellite Based Augmentation System (SBAS), guidance provides the prospect of a low-cost means for aircraft to become equipped to fly area navigation (RNAV) operations. The implementation of such RNAV operations within UK airspace offers potential benefits to both the airline operators and the Air Traffic Service Providers (ATSPs).

Integration of GPS/INS navigation systems is a common topic for aeronautical and road applications. The use of these technologies for personal localisation requires more than just portable sensors and a change of ergonomics; it requires a totally different approach for dead reckoning algorithms. This paper will focus on different human applications and reveals the particular problem encountered.

This, and the following four papers, were first presented at the NAV99/ILA28 Conference on ‘Loran-C, Satellite and Integrated Systems for the 21st Century’ held at Church House, Westminster, London, 1st–3rd November 1999.

Just 25 years ago, the author presented a paper at the 30th Annual Meeting of the United States Institute of Navigation (ION) entitled ‘Radionavigation in North America, the Next 25 Years’. The paper received much attention and was given the ION's Burka Award for the best paper of the year. The author attempted to predict the worldwide implementation of Loran-C and Omega while acknowledging that satellite technology was on the horizon. ‘Global Radionavigation – The Next 50 Years and Beyond’ builds on the previous paper and is an attempt to define the future of global radionavigation based upon a mix of terrestrial and satellite systems. The time it takes for satellite systems and augmentations to mature and the reasons for this extended period provide the foundation of the paper. Also discussed are: the time to achieve a full constellation of space vehicles having signal specifications that meet the requirements for safety-of-life, the political complexities to achieve international harmonisation of service, and the use of a common worldwide protected frequency spectrum. The need for terrestrial complements is presented from the standpoint of supporting satellite systems and as a back-up in the event of loss of satellite services.

This, and the following paper, were first presented during the European GNSS98 Symposium held at the Centre de Congrès Pierre Baudis, Toulouse, France, from 20 to 23 October 1998; however, both authors have provided updated scripts for use in this Volume of the Journal.

This paper provides an update of the development and implementation of the United States of America Federal Aviation Administration (FAA) Wide Area Augmentation System (WAAS) and Local Area Augmentation Systems (LAAS). It also addresses FAA efforts to implement these satellite navigation technologies into the US National Airspace System (NAS), as well as interoperability efforts concerning Satellite Based Augmentation Systems (SBAS) between the FAA and other worldwide Civil Aviation Authorities.

This paper presents the results of a study carried out in the Greater London area to assess and characterise the performance of the Global Positioning System (GPS) for vehicle positioning in urban areas. The performance assessment addresses, in varying levels of detail, the issues of service coverage, positioning accuracy, integrity and availability of service. The project was supported by Racal Survey Limited and is part of the wider research at Imperial College in the area of architectural design and testing of Advanced Transport Telematics (ATT) systems. The results highlight the shortcomings of GPS as the sole means for in-car navigation in urban areas and details the temporal and spatial considerations to be taken into account in the process of designing an integrated positioning system capable of meeting navigation requirements placed on ATT systems.

Satellite Based Augmentation Systems are being developed in Europe (EGNOS), the USA (WAAS), and in Japan (MSAS). As part of their support to EGNOS, NATS and Racal have developed and deployed a prototype SBAS system called the Northern European Satellite Test Bed (NEST Bed). NEST Bed uses GPS L1/L2 reference stations at: Aberdeen, Rotterdam, Ankara, Cadiz, Keflavik, and Bronnoysund. Data is sent to the Master Control Centre at NATS Gatwick Services Management Centre for processing. The resulting 250 bits-per-second message is sent to Goonhilly for up-linking by BT to the Navigation Payload of either the Inmarsat AOR-E or F5 spare satellite. NEST Bed was deployed and commissioned during summer 1998, and flight tests were successfully demonstrated at the September 1998 Farnborough Air Show where approaches were flown to Boscombe Down on the DERA BAC1-11 aircraft. In October 1998, a NATS/FAA flight trial was held in Iceland involving NEST Bed and the FAA NSTB. NEST Bed is also being used for SARPS validation.