To evaluate the aptness of a navigation system in a particular application, the designer needs to assess its performance over typical trajectories travelled by the vehicle itself. Moreover, he or she may be required to judge which components of the kinematics state may be better estimated (and which will not). The main contributions of this work are two novel and complementary performance measures that, in concert, allow for the assessment of a navigation system within the actual context of its application over specific trajectories. For a given on board instrumental configuration, the “excitability metric” permits the isolation of the contribution of the information conveyed by the vehicle's motion itself, while, the “sensability metric” measures the resultant overall quality of the kinematics state estimation. The same tools could help the designer planning appropriate vehicles manoeuvres in order to obtain a required precision for each estimated component. While emphasis is given on the mathematical justification of those metrics, their use is also illustrated with real flight data recorded from a sounding rocket.

The latest statistics on maritime accident alerts are again demonstrating a high percentage of false alarms from Emergency Position Indicating Beacons (EPIRBS) in Spanish waters. Of a total number of 243 received distress alarms, only three were real and 123 were never identified; a very similar situation exists in the rest of Europe. To address this problem, as well as IMO Resolution A.814(19)/23.11.95, there is a Spanish proposal to install a receiver (121-5/243/406 MHz) on board ships, so that the seafarer can detect accidental activation of an EPIRB. The installation of EPIRBS, which had seemed to be sufficient to solve the problem of locating vessels in distress, apparently needs the help of other tools. One such tool could be the very high frequency radio direction finder (VHF/DF) proposed in this paper. Recent experiments using VHF/DF carried on board the ships Salvamar Tenerife and Punta Salinas, in conjunction with the traffic control tower of the Rescue Coordination Centre (RCC) of Santa Cruz de Tenerife (Canary Islands), demonstrated a number of advantages which are described in this paper.

This paper was the basis of a presentation given on 9 November 2004 at Church House, London during the Institute's NAV 04 Conference. The author argues that AIS has been proven as a valuable aid to safe navigation, but requires comprehensive training to ensure its proper and effective use. Furthermore, he supports those concerned that using AIS in support of “homeland security” will make ships more vulnerable to attack.

There is currently considerable interest in the international regulations for preventing collisions at sea (the COLREGS). Suggestions for changes are made, but their validity is difficult to assess because there is little possibility of testing new proposals before they are introduced. There is, however, the possibility of considering the history of the COLREGS, and their effectiveness, as they have evolved over the years. In this paper, the author's aim is to look at the lessons that may be learned from one, particularly tragic, collision between the Princess Alice and the Bywell Castle in 1878. Opinions differ as to whether a study of history is likely to be a useful exercise.

Three textual works by Olaus Magnus (1490–1557) hold the key to the ‘compass’ on his invented island of Hvitsark, shown on his 1539 Carta marina. Although Olaus had little general understanding of the magnetic compass or of navigation in the Far North, he evidently did not intend the navigational device he drew on Hvitsark to represent a magnetic compass, but a sundial. His muddled ideas about the relationship between 12 wind-directions and direction-finding at sea by means of such a dial appear related to his second-hand information about a gnomonic navigational device used by the medieval Norse.

Dynamic trajectory prediction is an important topic in the field of navigation and positioning. Due to the drawbacks of a Global Navigation Satellite System (GNSS) receiver, the trajectory of the position always lags behind the dynamic platform's actual position, especially in highly dynamic situations. In order to solve the prediction of a dynamic trajectory, a generalised extension extrapolated model is proposed in this paper. The model utilises the current motion state and a priori position data of the platform, combines the interpolation and fitting method, adds the angle information as a constraint condition and solves the platform position prediction. In this paper, the feasibility of the generalised extended extrapolation algorithm is analysed theoretically and practically. Simulation results show that the prediction error is within 0.2 metres and experimental results show that the algorithm still has high prediction accuracy when a land vehicle platform is turned through a large angle.

The ever-increasing number of vehicles on the road has created a serious demand for traffic information not only on the move but also at the planning stage of a journey. While on the move, the driver will be able to re-route his/her journey avoiding traffic congestion, but this information could be even more valuable before starting the journey. Today there are differences between the three main ITS markets (USA, Japan and Europe). Japan is leading the way, with the introduction in 1995 of the Vehicle Information Communication System (VICS), which is a free service. Vehicles are equipped with VICS receivers taking information from a network of road beacons installed on main roads, transmitting traffic flows by infrared rays, wave beacons, and FM multiplex broadcast. Europe has been involved in driver information systems from the early '90s when RDS was developed, which is another free service, and most of the car radios sold in Europe are able to process RDS signals. Since then, new free services have been developed – for example, RDS-TMC. In the UK, the private sector has been heavily involved recently, its major player being Trafficmaster. The Trafficmaster system is based on a network of traffic detection sensors, which covers all major UK motorways and most of the major A roads, with plans to expand into the continent. Trafficmaster collects road traffic flows and disseminates this information to its subscribers via a range of technologies, including GSM. The quality of the information supplied by the free and subscription services can be improved by being fully integrated with on-board navigation systems and by providing more detailed and wider types of information. All current methods are described/analysed and compared in this paper, with future enhancement highlighted. One of the main limitations lies in current data transmission routes, which are not fast enough to support the data required for an optimal use of the system. Some technologies available will potentially allow the many service providers to transmit information.

This paper details the current status of the development of an ‘automatic’ low-cost system based on wireless communications technology to provide continuous tracking of the location of devices in all environments. This task requires a multi-disciplinary approach combining communications systems design, digital signal processing to extract ranges and, importantly, approaches from the field of geodesy to develop novel network positioning techniques for ad-hoc networks. Such a network will support a number of services relevant to crime management where seamless tracking is required. The paper discusses the process for developing the system, christened intelligent pervasive location tracking (iPLOT), with a particular reference to user and system requirements, and how these have been used to explore a network positioning strategy.

In the middle years of the 20th Century, few merchant ships were fitted with radar and, on those that were, shipmasters often looked upon it as a distraction from a watchkeeper's proper duties rather than as a useful aid to navigation.

For shipmasters of that persuasion, the only place to keep watch was outside the wheelhouse on an exposed bridge wing; mostly the starboard wing because the COLREGS (‘Collision Regulations’ or, more properly, ‘The International Regulations for Preventing Collisions at Sea’) required us to give way to ships approaching from the starboard side. Well, the bridge wing was an attractive place to spend a few hours on a calm, tropical night, but it could be highly disagreeable and sometimes, I thought, actually dangerous, in a North Atlantic rainstorm.

Since the advent of large-scale commercial aviation in the mid 1940s, a system of routes has been developed between airports serving the major conurbations of the world. To prevent collision between aircraft using these routes and off-route traffic, protection is provided to the routes and to the vicinity of airports by means of controlled airspace, airways (AWYS), control areas (CTAS) and control zones (CTRS). Zones commence at ground level and the base an area is at a defined altitude. Inside this controlled airspace certain rules apply which are more stringent than those applied outside, and all movements are subject to Air Traffic Control (ATC).

The monograph which follows has been prepared for the Institute by Wing Commander E. W. Anderson and Mr. J. B. Parker, working closely with Mr. D. H. Sadler. It was designed primarily for publication in book form; however, the Council has decided to publish it in the Journal as well, so as to give it the best possible circulation among members. This arrangement has meant varying slightly the normal style of presentation in the Journal and apart from the title page and page numbers there is no difference between the published book and the pages which follow.

In a previous contribution Professor E. G. R. Taylor has reviewed the development of the sea chart up to 1600, the year in which Edward Wright published his celebrated chart of the world on Mercator's projection. Wright's chart represents one of many minor incursions on the part of English cartographers into the field of nautical cartography, which at that time and for the next hundred years was dominated by the flourishing Dutch school of hydrography. It was not until the latter began to decline towards the end of the seventeenth century that the English cartographer really came into his own and began to produce charts to assist the navigator. Thus the evolution of the English nautical chart to its present state of development covers a relatively short span when measured against the whole background of maritime enterprise and endeavour.

The development over the past two hundred and fifty years has been sporadic rather than continuous, being characterized by sudden advances followed by long intervals of consolidation. Factors such as the needs of national defence, the invention of navigational instruments and advances in hydrographic surveying technique, have at various times acted as stimulants to chart evolution. Throughout the period under review responsibility for supplying the navigator with accurate charts has gradually passed from the many private publishing firms to a specially created national department.

A new application of the Omega navigation system is described in which a ground station is enabled to display multiple vehicle locations. Pulses from the vehicles are triggered by Omega signals and the times of arrival of the pulses at the ground station are processed to provide a ‘radar-like’ display of each vehicle's range and bearing.

This paper was presented at the eleventh Annual Meeting of the International Omega Association held in Quebec in August 1986.

This paper outlines a technique to represent terrain using tree structures, based on Morton ordering to avoid the use of pointers. This approach enables terrain data to be organised in a hierarchical form affording a trade-off between the speed of access to the terrain database and resolution of the terrain data extracted from the tree. A set of database access algorithms is developed that form the basis of path extraction needed for real-time mission management. Several examples are presented to illustrate the performance of the routeing algorithms developed in the paper.

Digital electronics have caused massive changes to navigation technology in the latter half of the twentieth century. This paper presents an alternative view to much of the commentary on the future of electronic navigation. It is written from a small craft perspective, although the principles are of value to commercial and naval shipping. Essentially, it proposes the development of environmental simulation as the basis for computer-hosted charting systems on vessels. This is drawn from the author's experience of developing the DyGeo system for environmental simulation, of which the navigation version forms a part. It stresses that much of the additional data we have placed on charts this century has been cultural in content, and necessitates a large bureaucratic system for its maintenance. An environmental system requires different types of inputs, but can be largely self-maintaining. The advent of the inexpensive, portable, personal computer has put this sort of facility in the hands of the leisure mariner as well as professional navigators.

This paper, and the following five papers, were presented during the Telematics Automotive 99 Conference held at the National Exhibition Centre, Birmingham, 13th to 15th April 1999. This first paper sets the scene for the more detailed technical aspects of the later papers. Copies of the full proceedings of Telematics Automotive 99 are available on loan from The Cundall Library.

Globalisation of both markets and supply has been nowhere more obvious than in motor cars. These vehicles create not only the most free economic pipeline known to man but also a revolution in personal freedom. They are unlikely to go away; we have to find ways of living with them by coping with the environmental problems and the many forms of traffic problem: congestion, driving and support skills and car crime. In other areas, notably manufacturing and commerce, automation and advanced communications have enabled radical improvements in quality, productivity and environmental impact. This effect has yet to reach road transport in volume; the environmental and traffic problems are growing at least as fast as the populations of vehicles grow. The risk with such an important enabler as telematics is that it is seen as a plaything for gadget-minded users, rather than a key enabler for ongoing use of the car in the face of unrelenting pressures of congestion and environmental damage.

In the January 1966 edition of this Journal Captain Wylie has given a lucid summary of the factors involved in the presentation on radar displays of true and relative motion. He also stated a conclusion on the combinations of display and ancillary equipment which he considers best satisfy the requirements for use when plotting to avoid collision at sea. Whilst acknowledging with respect all the work he has done to clarify the issues raised on this important but contentious subject over a number of years, a number of us has found it impossible to agree with his latest findings. As these may influence opinion in the shipping industry, the Board of Trade, the Courts of Law and the radar manufacturing industry, both at official and unofficial levels, they should not go unchallenged. Our disagreement concerns the priorities defined for display equipment and the method to be used for plotting. There can be no disagreement on academic principles.