I am honoured that the Royal Institute of Navigation has invited me to give the E. G. R. Taylor lecture for 1992. These lectures, held annually, were funded by well-wishes in various societies to celebrate Professor Eva Taylor's 80th birthday. As a scholar, Professor Taylor moved in many spheres. I have chosen a subject which seems appropriate to her pioneering work in the history of navigation and the marine sciences.

The recent history and background of the Channel Navigation Information Service (CNIS) have been well documented in this journal by my illustrious forebears, Captain Richard Emden and Commander James Neill. Whilst this paper describes some of the changes in the service since those papers were published, it may be appropriate to review the key events in the introduction of what was once a unique initiative, and remind the reader of the operational doctrine and philosophy of the system.

This paper is the fifth chapter of a series on the history of air navigation systems. Comments on the content of the paper would be welcomed by the author and the editor.

The unexpected commercial success of electronic charting systems has put an unusual pressure on the regulatory organizations to come up with some accepted international standard for this new technology. Unfortunately, the scope of this issue is far-reaching and touches the most sensitive nerves of maritime tradition and culture. This cumbersome legacy was noticeable from the very first US RTCM meetings on the subject and has conditioned the development of recommendations ever since.

This paper, written by an outsider, tries to look at the whole issue with an unprejudiced eye, arriving at a conclusion which casts heavy doubts on the wisdom of the current course and which advocates a different approach to take advantage of the incredibly powerful potential of this new technology – a technology which could radically change the rules and laws of commercial navigation to the benefit of safety and economy.

This paper and the following five papers were presented at the DSNS-94 Conference organized by the Institute from 18–22 April in London. The full proceedings, including some 78 papers, are available from the Director, price £40 (exc. P&p).

Aviation is becoming more and more reliant on information held in electronic databases for flight planning and for en route navigation use whilst airborne. Twenty or more years ago, aircraft were flight-planned along canned routes developed by specialist navigation departments with information derived from charts, flight guides and from the source Aeronautical Information Publications, the AIPS, themselves. The data was then output in the form of a paper flight plan. The move toward computerization occurred in the mid 1970s and the early systems relied on the construction of waypoint to waypoint routes. Today, aircraft are planned to fly on canned or random routes based on airway to airway segments dependent on characteristics derived from an aeronautical database. Though correlation with paper data exists, the industry has moved a significant way along the path to database dependence for ground-based flight planning. Moreover, the move towards reliance is not limited to the ground alone for, in the case of British Airways at least, all aircraft are equipped with some form of electronic navigation database. Few airlines, if any, with the notable exception of Swissair, have invested in the creation of a comprehensive global navigation database. The costs of creating, maintaining and verifying such a product are more than even large and relatively successful airlines are willing to pay. Instead, they buy in the required ground and air systems products from Jeppesen, Swissair, Racal and the rest. They procure a service secure in the knowledge that the data has been collated, verified and authenticated before publication and use. However, is this reliance misplaced perhaps?

Russia has had a quite unique development as a sea power. The 20th of October 1696 has been considered as the date of the Russian Fleet's creation when the supreme legislative body of Russia – the Boyar Duma – decreed that there should be a ship-building programme for the State's need. So, in 1996, we celebrate the tercentenary of the founding of the Russian Fleet (Figure 1).

The development of an electronic system which can be used for navigating water-borne craft has been going on for well over two decades. In fact, various digital representations of navigational maps have been in use since the concept of computers. The word ‘map’ is intentional, for in some cases, apart from the land outline and some navigational marks, they bore little resemblance to the paper navigational chart.

This paper describes the infrastructure and concept of two multi-site reference station differential GPS (DGPS) options being offered to land and marine users by Racal Survey. The infrastructure of the Racal SkyFix system is briefly outlined followed by descriptions of Racal's internetting and network capabilities.

The two systems are compared including infrastructure, differential data management, user coverage, datalinks and positioning performance in various parts of the world. The paper describes the design of each of the systems and the tests undertaken to assess their functionality, before going on to compare their performances under a variety of conditions. Emphasis is placed on the technical issues associated with multi-reference station DGPS including error sources, weighting observations and monitoring of the data. The fundamental approach of the systems is shown to achieve high data integrity which is necessary to develop the systems to their next phase.

Having described the two options, examples of various combinations of reference stations are used to illustrate the potential of the system and to show the increased performance over ordinary, single-station DGPS. The conclusions summarize the paper's findings and make recommendations for the future development of the system. The object of the developments so far have been to improve the quality of real-time offshore DGPS positioning. The internetting and network options are providing real-time results to illustrate the benefits and, together with SkyFix, offer significant developments in the ability of DGPS to provide accurate and reliable positioning over vast areas of the world.

Use of multi antenna GPS equipment for determination of a vessel's attitude holds some promise for the development of accurate and inexpensive attitude systems. An application for such systems might be to provide very accurate roll information for multibeam echo sounders.

The present state-of-the-art GPS attitude systems cannot meet the required accuracy and update rate for such applications. GEOTEAM A/S has therefore developed a PC-based system which combines GPS-based attitude with roll and pitch information from a Vertical Reference Unit (VRU) and heading from a gyro compass.

In such a combined system, the long-term high accuracy of a GPS-based attitude system is combined with the short-term accuracy and fast update rate of conventional VRUS and gyro compasses in order to achieve a resulting performance that is better than any of the systems. In effect, the GPS attitude is used to calibrate the VRU and the gyro compass in real time.

During the past year extensive tests have been performed with a system using a Trimble VECTOR II GPS attitude system with a 1 metre baseline between the antennas, both on a van (with an inertial navigation system as reference) and on a vessel. During November and December 1993 further tests were made with an Ashtech 3DF attitude system with longer baselines (7·5 m). These tests were made on a vessel where the combined GPS/VRU attitude was fed into a multibeam echo sounder. These tests were performed in cooperation with Simrad Subsea A/S, the multibeam echo sounder EM 1000 manufacturer.

This paper and the following 5 papers were presented at the Institute's NAV93 Conference on The Application of Advanced Systems. The conference was held in London in November 1993. The full Proceedings, containing some 42 papers, are available on application to the Director, price £30 for Members and £40 for Non-Members.

At the present day European ATC is exercised by a multiplicity of more-or-less autonomous control centres. ‘Flow Regulation’ is used roughly to match traffic demand to the capacity of the en-route ATC and of the destination airport. The ATC authority at the point of departure for a remote destination cannot however give any guarantee that the pilot will be able to follow his chosen trajectory. The filed flight plan and the departure clearance have been described as a ‘licence to get into the sky and see what happens’.

Anthropologists tell us that over 500000000 years ago the seas swarmed with some type of marine life and that during the Devonian period of 350 0000 000 years ago we could find the first species of monk fish that is now in high demand on the fish market place and sought after in strange hostile waters by European fishermen. The sharks were introduced to the planet at about this time and until this day have had the reputation of being the ocean's most voracious predators.

What's in a name? Well quite a lot really, and first of all, an explanation is required of our company name. PMT Limited is the trading name used for our core business area of North Staffordshire. The original full title was ‘The Potteries Motor Traction Company Limited’ but it is the abbreviation to PMT by which we have been known and loved for many decades – and who are we to argue with our customers? Under the terms of the 1985 Transport Act, we became one of the early management buyouts from the government-owned National Bus Company and chose to call the new company just PMT Limited.

For half a century, the Egyptians have been concerned about the coverage of all their local waters in the Mediterranean and the Red Sea with visual and electronic aids to navigation. As a result, they constructed several lighthouses and landmarks as separate entities. Long years of political friction and military conflict in the Middle East resulted in damage to the majority of visual and primitive aids to navigation, particularly in the Gulf of Suez (GOS), the Gulf of Aqaba (GOA) and the Red Sea.

Inmarsat commissioned the field study to be carried out by Signal Computing Ltd. in association with the Royal Greenwich Observatory. The study aimed to identify the commercial suitability of Wide Area Differential GPS (WADGPS) corrections. The corrections provided to users will be relayed via Inmarsat-3 geostationary satellites and are required to be valid over the footprint of an entire Inmarsat ocean region (approximately one third of the Earth's surface).

The study has been conducted within the Inmarsat Atlantic Ocean Region East. Trials took place over a five-month period to achieve a representative set of data. Six widely-distributed collection sites were used to ensure that the maximum duration of satellite data were received and that a representative model for atmospheric effects was obtained. Analysis is restricted to the use of GPS carrier and phase data obtained using the C/A code transmitted by Block II satellites only.

This paper presents the analysis of data collected during a four-day trial period. The ability to determine the GPS satellite ephemeris (independent of GPS broadcast ephemeris), Klobuchar model parameters tailored to the oceanic region, and satellite clock corrections using GPS data obtained from this limited deployment of collection sites is addressed. The primary degradation effects on stand-alone GPS positioning of Selective Availability (SA) are corrected using WADGPS, resulting in a significant improvement in position accuracy.

This paper presents a summary of the flight evaluation of the DGPS-INS hybrid navigation system conducted at the National Aerospace Laboratory (NAL). First, the configuration of the flight experiments, including ground facilities, the measurement system, etc. is described. Secondly, the design concept for a method of estimating navigation errors using a Kalman filter is presented. Thirdly, flight profiles employed in the experiments are defined, and the experimental results of GPS, DGPS, INS, in both stand-alone and hybrid modes are shown corresponding to each profile, and the improvement of navigation performance by the introduction of the DGPS-INS hybrid navigation system is experimentally verified. Fourthly, the future plan for research on the DGPS-INS hybrid navigation system at NAL is briefly explained. Finally, it is concluded that the design concept of the DGPS-INS hybrid navigation system available for future space vehicles has been successfully completed.

To ensure integrity of the Loran-C radionavigation system during non-precision approaches, an automatic blinking system notifies the user when the system is not functioning within specifications. To be certain that timely detection of this blinking can be guaranteed, one of the requirements imposed on an airborne Loran-C receiver is that it should flag an alert when the signal to noise ratio drops below –6 . This paper addresses some blinking detection methods, that will ensure safe operation beyond this –6 dB limit. A preliminary version of this article was presented at the Wild Goose Conference in Birmingham, August 1992.

This paper describes a low-cost, in-vehicle route planning and driver information system being developed for use within the DRIVE PLEIADES (London–Paris corridor) project. The system integrates vehicle position information from a GPS receiver, traffic condition messages broadcast from both RDS-TMC and radio paging, and road network information from a route planning system. Instructions describing the route to be followed are presented to the driver on a dashboard-mounted LCD and in spoken form. The system tracks the calculated optimum route and gives instructions for the next section of the route to be covered. The optimum route is continuously recalculated, reacting to TMC messages and the vehicle's location.

Even today much time is lost in bringing effective help when an accident with a truck carrying dangerous goods occurs. The location of the accident is often not well described by the people reporting it. Often it is difficult to determine what sort of freight a lorry is carrying, for example when the vehicle is burning, and sometimes the fire brigade does not bring the appropriate extinguishing equipment for the first help approach. Now an emergency location system is under development which will remove all these disadvantages. For immediate help on car accidents, an automatic alert message is transferred from the crashed vehicle via the emergency call centre to the fire brigade, the police station or the headquarters of an ambulance. The alert is initiated by a crash sensor within the car or the truck. The data channel between vehicle and base can be a radio link or, for longer distances, a mobile telephone connection using CNET or GSM. AS help is faster and more effective with this system, environmental damage caused by dangerous goods can be reduced.

In Stuttgart the mobile part of the DGPS-based emergency location system has been integrated in several vehicles. The full system is being tested within a field trial of a pilot project called STORM (Stuttgart Transport Operation by Regional Management), which is part of a programme of the European Community. The results of these tests are summarized in this paper. The integration of the system into fleet management applications is also considered.