In order to navigate and thereby survive in a hostile environment the Inuit have developed a sophisticated body of knowledge that makes travel possible even during a blizzard or white-out. This unique skill was developed from a thorough understanding of the properties of snow and local meteorology. Problems of space, time and distance are also taken into account by Inuit navigators but this is done with minimal use of quantification and abstraction. However this highly practical form of navigation in which the Inuit deal directly with their environment is none the less scientific and empirical.

In 1971 the author attempted a single-handed sailing of the North West Passage and in 1973 completed a crossing of Arctic North America by dog team.

This paper, with Dr Lyon's was presented in Paris in November 1983 at an international colloquium organized by the Centre d'Etudes Arctiques of the Centre National de la Recherche Scientifique, by whose kind permission they are here reproduced. The theme of the conference, at which some 35 papers were presented, was the Conquest of the North Pole; the subjects covered included both the history of Arctic exploration and contemporary problems and the future of polar transport, sea and air. Mr Kerr is Director of the Canadian Hydrographic Service's Atlantic Region; both he and his co-author are at the Bedford Institute of Oceanography in Dartmouth.

The two papers which follow, by the late Captain (and Dr) Charles Cotter, are the last of a number of papers he submitted for publication in the Journal, and which have appeared from time to time. Now that he is no longer with us it seems appropriate that they should be published simultaneously.

We describe a new type of radio navigation and tracking system which, unlike conventional systems, does not depend on a costly infrastructure of coherent radio transmitters. This new system measures positions using spatial, rather than temporal, coherence and can therefore use any existing radio transmitters set up for any purpose. We describe the principles of operation, applications and present results obtained with a demonstration unit (in Cambridge) which can measure the position of a motor vehicle to a precision of about 5 m using local medium-wave public broadcast transmitters.

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.

In this paper, which was read at an Institute meeting in London on 11 February 1976 with Mrs. Mary Pera in the Chair, Captain Cockcroft examines the incidence of collisions in relation to the numbers and classes of ships at risk and their trends, pre-war and post-war. Total and partial losses are included and compared with other forms of loss, e.g. strandings.

In several previous papers statistics of marine collisions have been given for particular areas such as the Dover Strait, Western European rivers, the Baltic Sea and Japanese waters. This paper is concerned with worldwide statistics with particular reference to sea collisions. The information is mainly derived from the Statistical Tables published by Lloyd's Register of Shipping and from the casualty reports compiled by the Corporation of Lloyd's. Statistics of shipping casualties must obviously be related to the number or tonnage of vessels at risk; for insurance purposes loss ratios are usually expressed in terms of tonnage lost to tonnage afloat but navigators are more concerned with the number of casualties and number of vessels at risk in various categories.

The rapid developments of mini-computer technology and the introduction of integrated navigational electronic equipment in ships calls for a reappraisal of bridge design as a matter of urgency. Several research projects have been carried out in recent years and all have concluded that ‘a completely fresh outlook is required rather than work on existing designs and on methods which are regarded as both accepted and acceptable’. Shipowners and shipbuilders need to understand the requirements of the men who will be responsible for the safe handling and navigation of the ship and to choose between stagnant inefficiency and economical gain through proficiency. The standard central command-post layout design should comprise flexible units adaptable to every type of merchant ship, except of course such specialized vessels as oil rigs.

A simple method is described for estimating the angle of misalignment of a two-component electromagnetic log, using the covariance properties of the measured components when a ship is steered in a constant cross wind at a number of different speeds. It is shown that, with the present accuracy of radar fixing, allowing for misalignment has a very small effect on the determination of sensitivities for an absolute calibration. However the effect of misalignment is important when cross-calibrating the athwartships components of two electromagnetic logs.

When designing a bridge for a naval vessel the designer faces a number of requirements which are quite different from those of a merchant vessel. Besnard states that besides a good view, the officer of the watch requires by him the instruments for determining direction and distance or speed, position finding instruments and other electronic aids, and the means of communicating with the helmsman and engine room as well as some check on these communications. He concludes that a cockpit arrangement of the instruments would suit the requirements. Rees, on the other hand, doubts whether the officer of the watch would remain alert for long periods when sitting in an enclosed compartment, and suggests that a cockpit arrangement is only appropriate where there is little space. Further he argues that the duties of the officer of the watch extend beyond those of simply directing the ship.

The method of finding the latitude of a ship at sea from an observation of the Sun or other body near the meridian is practised extensively in the Merchant Navy. The history of the method, which dates from the middle of the eighteenth century, is full of interest: and the ex-meridian problem is almost as celebrated in the history of nautical astronomy as the double altitude problem. Considerable attention was devoted to the ex-meridian problem during the last century—a period which was, in truth, the golden age of astronomical navigation. Many ingenious solutions were contrived and a diversity of ex-meridian tables were constructed, all aimed at facilitating the problem of finding latitude at sea.

Inertial navigation systems represent the ideal in automatic navigation. They operate entirely without external assistance, other than information as to their starting conditions, which makes them of great interest to both military and civil operators.

The navigator at the present time relies greatly on both optical devices and on radio systems utilizing electromagnetic waves ranging in wavelength from millimetres up to hundreds of metres. The laser extends the coherent properties of radio waves into the visible part of the spectrum. It is natural therefore to expect that this increased facility should lead to the possibility of devising systems based on the laser which might help to overcome problems that still exist in navigation.

It is the purpose of this paper to describe the principles and performance of present-day lasers, to survey some of the techniques used in navigation in order to discover those in which the laser might conceivably play a useful part, and to comment on the laser's advantages and disadvantages in comparison with existing methods. Finally, a particular form of laser called the ‘ring laser’ is described and discussed in some detail. The ring laser is of great interest in that it provides a completely novel way of measuring direction relative to inertial space, and is therefore a possible competitor to the gyroscope for inertial navigation. The ring laser can also measure the velocity of a transparent medium moving relative to it, which could be of use in determining vehicle velocity.

The requirements of navigation entering or leaving harbour or in narrow waters are exacting, and a very accurate position is usually essential. For this reason it is believed that inertial techniques should be applied in the first instance only to ocean navigation as, although the system will give the ship's position continually, the accuracy will be of the order of one mile.

The latitude and vertical references are absolute, but the longitude reference is relative to a known starting point. Besides position, an inertial system can also provide course, sidereal time and roll and pitch and, by comparison of successive positions, course and speed made good, and leeway. Furthermore the system could be used to feed position into an automatic plotting table, with a chart of suitable scale superimposed, so that the vessel's geographical location would be visible at a glance.

There are two approaches to the study of errors in astronomical observations at sea. One is to collect as much information as one can from practising navigators; the other, described here, is to carry out controlled experiments with the object of breaking down the various causes of error, a virtually impossible task if the first approach is adopted. In both cases a large mass of data must be carefully studied and analysed, and this is particularly important where one aims to resolve the errors into separate components (those due to dip uncertainties, horizon, body, degree of twilight, and sea state).

This paper, which was presented at an Ordinary Meeting of the Institute held in London on 15 November 1963, sets out to comment on certain aspects of the long-range navigation of civil aircraft. It concentrates on three areas where there seems to be room for improvement: reliability (a failure rate of 1 : 10 is suggested); the integration of navigation information into a single system and display; standardization of navigation facilities so that all aircraft can use the same basic system.

It is concluded that a reliable system is required down to ground level, an indication of reliability should be presented to the pilot, that high reliabilities can be obtained by comparison of ground-based and self-contained aids, that a navigation computer is necessary to reduce the information to a presentable form, and that the use of very low frequencies seems to be the most promising way of developing an aid along these lines.

Disasters result from the breakdown of navigational faculties. Those concerned with the ‘practical’ aspects of navigation naturally assume a standard and infinitely flexible nervous system by which the individual can adjust to the stresses created by great speeds in the absence of habitual sense information. This paper outlines the nervous basis of adjustment to environment (personal navigation), the forms of breakdown in disease, and the nature of hallucinations. Some forms of disturbing experiences likely to be felt in modern navigation are predicted and explained. Such problems are seen as integral matters of aviation planning, design and practice.

‘The main aim … is to enable interested persons with quite different backgrounds of knowledge and experience, to come together and consider collectively a subject of common interest from their various standpoints.’

(A. M. A. Majendie, ‘The Significance of Blunders’, this Journal, 12, 28.)