The tip of the Chukotskiy Peninsula in the Soviet Far East is 86 km from mainlandAlaska and its mountains are clearly visible from St Lawrence Island. It is a ruggedtreeless land that straddles the Arctic Circle between the Bering Sea and the ArcticOcean. In winter it is snow-covered and the sea stays frozen until May.

This paper is the fourth chapter of a series on Air Navigation Systems during theperiod from the early oceanic flights and the inception of commercial aviation to the introduction of INS in civil aircraft. Comments on the content of the paper would be welcomed by the author and the editor.

Life is more intense today than was shown in the film, and direction finding is somewhat more precise. We now know where aircraft are, rather than where they were some minutes earlier, (for at least most of the time!) and not every air traffic controller we employ speaks like an early BBC announcer.

Ships' bridge watchkeeping, although the prime task of the officer of the watch, makes very low task demands in terms of information processing and required speed of response compared to most other vigilance tasks. Consequently, performance of the visual lookout task is difficult to describe and evaluate systematically. Results from an on-board observational study show that lookout lapse periods can be economically described by simple mathematical models, which assist in comparison and evaluation of task performance.

The transmissions from GPS and GLONASS navigation satellites include information about the state of those transmissions as perceived by the control centre. In the case of GPS, for example, this information is contained in the data stream in Subframe 1 Word 3. However, with some of the failure conditions that can arise there is a delay of the order of half an hour before this message is altered to signal that a failure exists. A situation can therefore arise when the satellite signals that all is well, whereas in fact it is not. The very high levels of integrity which civil aviation require before satellite navigation can be used with confidence therefore means that the warning messages from the satellite must be augmented by some other form of monitoring. Two alternatives exist: (1) to have a monitor at some fixed and surveyed ground location which broadcasts a warning to the navigating aircraft when there is a malfunction (ground monitoring), or (2) to arrange for the navigating receiver to perform its own internal monitoring, known as receiver autonomous integrity monitoring (RAIM). Each alternative is beneficial in its own way.

This paper was presented on 20 February 1991 at a half-day meeting on haven charts for yachtsmen. The meeting was organized by the RIN in association with the Honourable Company of Master Mariners, the Royal Cruising Club and the Cruising Association. Adam Kerr is a Director of the International Hydrographic Bureau, but the opinions provided in this paper are his own and should not necessarily be construed to be those of his organization.

In the early 1960s, Ferranti developed a 4-gimbal miniature inertial platform (approximately 8 inches diameter) for a number of applications, including the RAF Harrier and Phantom Inertial NavAttack system and for various satellite launcher projects. This platform used the Type 125 floated rate gyro (adapted from a design by Singer Kearfott, and originally referred to as Type M2519).

This, and the following five papers, are a selection from those presented at the RIN91 Conference on Small Craft Navigation. The Conference was held at the Warsash Campus, Southampton, over the weekend 6–7 April 1991. Copies of thecomplete proceedings are available from the Director, price £30 to non-members and £20 to members (exc. postage and packing).

This paper and the following five papers were presented at the NAV90 Conference on Land Navigation and Information Systems. The Conference was organized by the Institute in September at the University of Warwick. Complete sets of the proceedings are available from the Director, Royal Institute of Navigation, price £60 (to RIN members).

This paper takes a global overview of technical developments in vehicular navigation. From this vantage point, the author gives his perception of some of the critical issues involved in the major shakeout and consolidation which he expects to occur during the next one or two decades, and he speculates on the outcome.

Agriculture in the U.K. has, since the late 1940s, enjoyed government subsidy and insulation from free market forces. However, the post-war philosophy of ‘every acre counts’ no longer holds true in the face of surplus production and a growing public awareness of the countryside and environmental issues. Legislation relating to water pollution, public rights of way and price support mechanisms are all contributory factors to the radical changes which agriculture is undergoing at the present time. Investigations have shown a need within agriculture for the efficient use and handling of data relating to the land, and a need for new technology to exploit the inherent spatial variability of, for example, the soil. This paper will discuss the development of an agricultural vehicle positioning instrument and future research which will address the needs which have been identified.

In 1987 a special meeting of IALA held at Trinity House in London expressed a common purpose to enhance and expand existing Loran-C coverage in North-West Europe and the North Atlantic. After two years of negotiation, agreement was finally reached in January of this year to proceed with the project. The countries involved are Canada, France, Germany, Iceland, Ireland, Netherlands, Norway and the United Kingdom, with cooperation from the United States and Denmark. They will re-equip six existing United States Coast Guard stations and use two French stations together with four new transmitters to provide four chains, covering the whole of NW Europe and most of the North Atlantic.

Primarily in response to airline pressures for fuel economies, ICAO, the International Civil Aviation Organization, established a study programme early in the 1980s to determine the feasibility of halving the vertical separation minimum (VSM) used above FL 290 to 1000 ft. This paper is the first of a 3-part article describing a European contribution to this programme. After outlining the aims and organization of the experimental work, it describes the choice of methodology available to measure height-keeping errors and gives an indication of the measurement accuracy achieved. Details of the data collections, the risk calculations performed and the factors found to affect height-keeping accuracy are given in Parts II and III. Overall, the work has shown that whereas it would be technically feasible to introduce a 1000-ft VSM in the North Atlantic region, other measures would be necessary before it could be used in continental airspace. Today, in certain areas, the need for a reduced VSM has become even more pressing in order to achieve the gains in airspace capacity necessary to handle rapidly growing volumes of air traffic.

The current state of the shipping and ship-building industries indicates that they are having difficulty surviving. This is especially so in Japan, which imports oil, ores, food and most of the materials used in manufacturing products for the domestic and foreign markets. The issue of maintaining stable and effective transportation overseas is, therefore, vital.

What are we doing it for? Datatrak designed, built and prepared for the transport market, a complete Automatic Vehicle Location and Reporting System (AVLRS) that covers 95 percent of the road system of Great Britain.

High-speed navigation brings its own problems. These are mainly concerned with time and space, and the inability to carry out many of the normal functions associated with navigation due to the motion of the boat. The time available for navigation is compressed and, at 30 knots, a buoy sighted 1 mile ahead is just two minutes away. Decisions have to be made quickly and the navigator needs to be presented with information in a readily usable form. Many of the traditional techniques of navigation can no longer be used easily, and new techniques which take into account the high-speed environment have to be developed.

Engine performance data, including fuel consumption data, is freely available in the sales literature published by most of the major manufacturer' or marinizers of diesel engines. Boatbuilders, similarly, quote the fuel capacity of their craft in all but the most superficial of brochures.

A navigation strategy for an autonomous land vehicle (ALV) based on the Defence Geographic Database is currently being developed under the auspices of. the Mobile Advanced Robotics Defence Initiative (MARDI). The database is hierarchically structured, and supports the storage of an unlimited number of attributes for each geographical feature. It also expressly identifies the interconnectivity of adjacent features, making it ideal for automatic route calculation. Tactical battlefield information is being combined with the database resulting in a composite link-node map which will be searched for optimum routes using standard algorithms. Both military and geographical criteria will be simultaneously optimized. Waypoints suitable for machine vision techniques will also be extracted and used to confirm the ALV location.

One of the most important factors for the safety of navigation is to ensure proper collision avoidance manoeuvres in a congested traffic area. There are many aids for this purpose; for example, an ARPA, which is mandatory for certain ships and which is expected to be effective.

The Automobile Association, Ordnance Survey, Philips BV and Robert Bosch GmbH are collaborating in a project to create and test a prototype navigation database. The project, (PANDORA–Prototyping A Navigation Database Of Road-network Attributes) which is being managed by consultants MVA Systematica, is supported by the European Community's DRIVE initiative.

The data requirements of future vehicle navigation systems such as CARIN from Philips, Travelpilot/EVA from Bosch and the Autoguide scheme for London have been examined. Digital street networks have been extracted mainly from Ordnance Survey's large-scale digital mapping, and the necessary road and traffic attributes have been collected by the AA. These data have been integrated into a specially-designed prototype database for parts of London and Birmingham and the major interconnecting roads. Data have been abstracted from the database and supplied to Bosch and Philips using the Geographic Data Files (GDF) standard developed in the DEMETER project. This dataset is being tested in field trials using prototype vehicle navigation systems. The dataset will also be provided to the DRIVE Project ‘Task Forc European Digital Road Map’ as benchmark test task number 12.

This paper describes the project, dealing with its objectives and relationship to other European initiatives, the work undertaken, the standards utilized and developed, its results and conclusions, and the lessons learned with respect to provision of data for larger areas of Europe. A glossary of technical terms and abbreviations is also included.

There is a great sense of movement and progress in navigation today. The excitement lies in the ability to do things which were not possible with traditional media or at best were difficult and time-consuming to achieve. So this paper is not about the desirability nor the timescale of the ECDIS (Electronic Chart and Display Information System) replacing paper charts for primary navigation. It is about the flexibility and creative power opened up by new technology.