This paper and the following four papers were presented at the EURNAV-96 conference, held in London, 18–19 June 1996 and organized jointly by the Royal Institute of Navigation and the German Institute of Navigation. Copies of the full proceedings, comprising some 22 papers, may be obtained from the Director of the RIN.

I am delighted to be here at the EURNAV-96 conference. Vehicle navigation, location and control is a special interest of mine and I have no doubts about its value and potential.

Road transport plays a vital part in the UK economy and will continue to do so for the foreseeable future. However, the environmental issues surrounding transport are also of growing concern to the nation, with roads seen as a key element in the environmental debate. These two issues are in conflict, with one pointing to the need for greater road capacity to accommodate more vehicles while the other suggests a limit on road space and fewer vehicles. The Highways Agency has a responsibility to help resolve this dilemma and is doing so by placing increased emphasis on making more efficient use of existing roads.

ROMANSE — Road Management System for Europe — is multi-million pound pilot project based in Southampton. It aims to use Advanced Transport Telematics (ATT) to develop the city as a model for transport management systems across Europe. ROMANSE achieves this by providing realtime traffic and travel information to influence travel behaviour, increase the use of public transport, maximize the efficiency of the transport system and provide high-quality information for use in strategic policy decisions.

Autonomous Intelligent Cruise Control (AICC) will be marketed by a number of vehicle manufacturers before the end of the decade. This paper will describe AICC and the next generation systems currently being developed and validated within the EC Fourth Framework project, Anti-Collision Autonomous Support and Safety Intervention SysTem (AC ASSIST).

The currently available cruise control systems which maintain a fixed speed are a well-known form of longitudinal driver support. The fixed speed cruise control becomes less useful with increased traffic volumes, as the driver must disable the system when a slower preceding vehicle is encountered.

In a paper in 1988 it was confidently predicted that there would be a commercial dynamic route guidance system operating in London by about 1992. When in 1993 a review was conducted of why the optimism of the late 1980s had not been played out in reality, there were four main reasons given for the delays:

(i) Availability of mapping data.

(ii) Establishment of good traffic monitoring networks.

(iii) Choice of communication method.

(iv) Need for integration with other Intelligent Transport Systems (ITS) services.

Integrated Command, Control, Communication and Information (C3I) Systems have developed a language of their own, drawing heavily on acronyms and information technology terminology, resulting in the impression being given to the uninitiated that either a black art is being practised or at least there is a mystique unknown in other complex systems. No master plan or model exists for C3I systems, and their very existence is predicated primarily on the need to fulfil two basic requirements. First, they exist where there is a need at the highest level of management of an international or national authority, or of a large company, or of a large organization, to exercise real-time optimum use of the total and diverse resources available to the corporate body in pursuit of its mission, charter or commercial goal. Secondly, at the lowest level, C3I systems exist to help an individual, or a machine, or a sensor, to perform a given task or rôle more effectively. The integration of emergency services and the operation of large modern transportation systems are among the civilian systems that stand to gain most from the use of integrated C3I systems.

As long as man has ventured to go to sea, sailing directions have existed. Man's survival depended upon knowing the best fishing and hunting places and how to find these were secrets, told only to family or friends.

Later, sailing directions covered areas in the world where trade or new settlements had begun and, as early as 500 years B.C., some of these sailing directions were written down. They covered the Mediterranean Sea and part of western Europe and they were called PERIPLUS meaning ‘sailing around’. They contained almost the same information as sailing directions today, namely: harbours, anchorages, currents, possibilities for fresh water, provisions and other supplies.

This paper is the sixth chapter of a series on the history of air navigation systems which have appeared from time to time in the pages of the Journal since 1988. Part II of this chapter will appear in the next issue of the Journal.

The author acknowledges the assistance of Bath College of Higher Education and, in particular, Dr Terence Rodgers, The Royal Aeronautical Society, The Royal Air Force Museum, and Philip Saxon of the Royal Air Force Historical Society.

One of the definitions of Navigation that gets little attention in this Institute is ‘communication by canals and rivers’ (Oxford English Dictionary), and which our French friends call La Navigation. I have always found this subject fascinating, and have previously navigated the Rivers Mekong, Irrawaddy, Hooghly, Indus, Shatt-al-Arab, Savannah and Rhône. During the middle of 1995 I travelled by barge from the North Sea to the Black Sea via the River Rhine, the Rhein—Main—Donau—Kanal (RMDK) and the River Danube, a distance of approximately 4000 km. This voyage has only recently become possible with the opening of the connecting RMDK at the end of 1992, but has been made little use of because of the civil war in the former Yugoslavia.

In the early sixteenth century, Portuguese navigators on voyages outside the tropics ran into an unexpected problem in navigating with the plane chart since the latter took no account of the convergence of the meridians. Voyages between Brazil and the Cape of Good Hope were accomplished much faster than the chart led them to forsee. To overcome this problem, were Portuguese pilots of the first half of the sixteenth century using globes to set their courses with on great circle courses? The general opinion is that they were not. Yet the mathematician Pedro Nunes (1502–78) describes in a short treatise entitled Tratado que ho Doutor Pedro Nunez fez sobre certas duvidas na navigação (published in 1537, but probably written in 1534) how the navigator Martim Afonso de Sousa, on his return from the east coast of Brazil in 1530–2, had asked him to solve several problems of navigation encountered on the voyage.

This paper summarizes the results of Phase 3 of the Arctic Tanker Risk Analysis Project (ATRA) which provided a prototype Tanker Navigation Safety System (TNSS). TNSS is a ship-board risk management system capable of route planning and decision support based upon a knowledge database. The objective of the project was to provide timely risk assessment information to a mariner or decision-maker in a system capable of integration with existing ECDIS or shipboard PC systems. The historical information was to include: accident location, frequency and type, ice, wind, visibility, environmental sensitivity and other factors. The specifications of the TNSS prototype were expanded so that risk could be assessed for each track in a route plan by applying a predictive accident model patterned after the navigation and collision avoidance process.

This paper describes an advanced method, and the corresponding algorithms, which could provide a high precision Wide Area Differential GPS (WADGPS). The service would be suitable for single or dual frequency users, and could be introduced with very few reference stations. The two main components of the service are a precise, near real-time orbit determination of the GPS satellites, and an accurate estimation and modelling of ionospheric and tropospheric effects. Broad principles of the processing algorithms and results of both simulation and real data tests are described. User positioning accuracies of better than 2·5 m (r.m.s.) in plan and 3·0 m (r.m.s.) in height are achieved by both single and dual frequency scenarios.

Wide Area Differential GPS (WADGPS) is being developed to overcome the main drawbacks of conventional or Local Area Differential GPS (LADGPS), where positional accuracy of a user degrades as the reference-to-user separation increases. The spatial decorrelation of the error sources, notably the atmospheric propagation and satellite orbital errors inherent in GPS, are the main causes of this accuracy degradation. Several organizations are involved in WADGPS research, and different conceptual approaches have been suggested. The proposed methods all share a common basic assumption: that the error sources which affect the system are broken down into individual error components and are modelled separately. The variance between the different techniques comes from the way in which the different error components are modelled.

The feasibility of using a genetic algorithm to optimize a fuzzy fixed rule based autopilot is considered in this paper. Simulation results are presented to show the applicability of the approach. It is concluded such a procedure gives more credence to the resulting design than can be achieved by totally heuristic methods.

As a result of the general recognition given to the robustness qualities of fuzzy control algorithms, studies have been undertaken in the marine field to develop autopilots based on this approach. Indeed, a fuzzy autopilot was recently installed in a small leisure vessel and very successful fullscale sea trials were undertaken. In the past, the main problem in designing a fuzzy autopilot, or any other fuzzy controller, has been the reliance on purely heuristic methods to obtain an optimum solution. To compensate for such shortcomings in the design cycle analytical approaches are now being proposed.

There are two places where landsmen and seamen are likely to come into conflict: (i) in the pubs around Portsmouth Docks; and (ii) in tidal estuaries such as the Thames. There is, however, an intermediate class of person, represented nowadays almost entirely by more or less amateur oarsmen and women, which is that of watermen. I am proud to consider myself a member of all three.

Many texts stress the need for marine sextants to be held precisely vertical at the instant that the altitude of a heavenly body is measured. Several authors lay particular emphasis on the technique of ‘rocking’ the instrument in a small arc about the horizontal axis to obtain a good sight. Nobody, to the author's knowledge, however, has attempted to quantify the errors involved, so as to compare them with other errors inherent in determining celestial position lines. This paper sets out to address these issues and to pose the question: what level of accuracy of vertical alignment can reasonably be expected during marine sextant work at sea ?

When a heavenly body is brought to tangency with the visible horizon it is particularly important to ensure that the sextant is held in a truly vertical position. To this end the instrument is rocked gently about the horizontal so that the image of the body describes a small arc in the observer's field of vision. As Bruce Bauer points out, tangency with the horizon must be achieved during the process of rocking and not a second or so after rocking has been discontinued. The altitude is recorded for the instant that the body kisses the visible horizon at the lowest point of the rocking arc, as in Fig. 2. The only other visual clue as to whether the sextant is vertical is provided by the right angle made by the vertical edge of the horizon glass mirror with the horizon. There may also be some input from the observer's sense of balance and his hand orientation.

Following Dag Pike's earlier paper on this subject I would like to discuss some points and address the problems of collision avoidance with High Speed Vessels within the framework of the present International Regulations for the Prevention of Collisions at Sea (COLREGS). Generally, a valid case for limited modifications to the COLREGS may be presented, but they may not be as wanting as suggested by Mr Pike.

May I congratulate Chris Perkins and Tony Redfern for their excellent paper in the May issue of the Journal. For many years I have read in the Journal, and on occasions listened to, learned ladies and gentlemen discoursing on the subjects of safe navigation and collision avoidance. Also to what I believe are their misguided wanderings into ‘ship domains’ and assumptions that ships behave as atomic particles. Thus it was very refreshing to read the latest and practical contribution by Chris and Tony. Well done chaps!

I am disturbed by Perkins and Redfern's paper in the May 1996 Journal.

The COLREGS have been developed over many years of tinkering and tuning. They are not designed only for educated European masters driving big merchant ships. The users; fishermen, yachtsmen, oarsmen, tugmasters, Rhine bargemasters, and Yangtse junkmen, etc, are from all educational standards and from all the world's cultures. The COLREGS are now well-known. There is such a huge investment of time and effort, of learning by millions of different people, that the prospect of tampering with their fundamentals is horrific, even if it would suit a small class of user belonging to the more advanced countries. Change is painful, and too much change, too fast, kills. Compare the practical decision not to change the side of the road on which we British drive: it might be convenient, but it would cost too much. The same applies to the COLREGS.

I am pleased to see that, in light of my critical evaluation, Arne B. Molander has reevaluated a number of points in his analysis, and has revised his proposals of Columbus's alleged use of the Moon for determining his longitude. However, it is disappointing that these latest proposals again do not seem to have been thoroughly considered.

Since it is clear that Columbus's East–West position fixes are not correlated with visible lunar-planetary conjunctions, Mr Molander's latest hypothesis is that Columbus observed a dark-horizon moonrise or moonset near each conjunction – which usually can be done whether or not the conjunction itself is visible. However, it is entirely unclear how such an observation can be converted into a longitude. Reading attentively, we can glean a few details of this process: only a single observation is required, since some positions are computed within a few hours of the purported observation; and Columbus apparently used the Ephemerides of Johann Miiller, since errors in that ephemeris are alleged to have caused errors in the computed longitude. In his 1992 paper, Mr Molander asserted that timing of the conjunction is not required by this method, because Columbus somehow utilizes the Moon's daily topocentric motion. But how this datum is utilized, and in fact all details of the longitude determination itself, are entirely obscure.

I believe that it is timely that Dr. B. D. Yallop, Head of HMNAO, has responded to criticisms and the discussions surrounding the inclusion of ‘Sight Reduction Procedures’ and ‘Sight Reduction Tables’ beginning with the 1989 edition of the Nautical Almanac. As my name was mentioned by Dr Yallop, I would like to set out my own views on some aspects of those discussions because I believe that both the ‘theoreticians” and the ‘practitioners” positions have become too polarized.