Many discussions have taken place regarding the feasibility of plotting when using radar in reduced visibility and it soon becomes apparent that there is confusion in what each of us considers by the term ‘plotting’.

These notes are to suggest definitions of the various stages of plotting and to consider the conditions under which each is necessary.

Radar plotting can be divided into three stages:

(a) Record plotting

(b) Deductive plotting

(c) Forecast plotting.

In the bicentenary year of the birth of Matthew Flinders at Donington, near Boston in Lincolnshire, it is my privilege to present to Members of three notable British societies some details of the life and work of this great hydrographer.

His surveying and charting impact was made entirely in Australian waters and he is probably better remembered in that country today than he is in his homeland. It is my hope that my discourse, added to the many activities that have been arranged in Britain this year, will do something to rectify this situation. My talk will attempt to tell the brief story of Flinders' 40 years of life and work, beset in his later years by many misfortunes. I will also examine in some detail how Flinders conducted his surveys by taking a few isolated examples, and finally briefly review the results of his labours.

The British Nautical Almanac was first published by Nevil Maskelyne, the Astronomer Royal, in 1766 for the year 1767 and the chief table in it was of lunar distances, which were tabulated at intervals of three hours to the nearest second of arc. On the bicentenary of its publication the theory and practice of lunar distance observation and reduction were reviewed in this Journal.

Captain Wylie's extensive and detailed criticisms of the Sailing and Steering Rules in the new Collision Regulations (Journal, 26, 365) were published in the January number of Navigation, the journal of the French Institute of Navigation, with an editorial note by Professor Hugon. The note and Captain Wyile's reply are given below.

The Collision Regulations are due for revision by Imco in 1972 and already governments and other agencies are formulating proposals for consideration by its Maritime Safety Committee. The Institute's working party on the subject, which was formed initially to try to lessen the area of disagreement between people who had put forward positive proposals over the last few years, has now formed a cohesive view and formulated a set of recommendations. These are given in the interim report which follows. In the normal course of events things would have been allowed to run their course and the final report published only after further meetings of the working party which has still to reach firm conclusions on a number of points (for example on the precise form of the manœuvring diagram referred to at the end of Section 2 and in proposition (14), and on the whole question of lights). However, time is short and it seems probable that if the views of the working party are to have any effect on the deliberations of Imco, they must be made known straight away. The report (of which M. W. Richey is the author), therefore, which embodies the whole area of agreement between the members of the working party, is published here in interim form.

Dr. Calvert has expressed some unease from his own point of view about propositions (1) to (19) and it is hoped in the final report to publish an appendix by him suggesting a totally new approach to the whole problem of collision avoidance by manœuvre. It is hoped also to publish an appendix by Admiral García Frías describing the system he proposes. Both these contributions are perhaps likely to be of long-term rather than immediate significance.

The author, a Master Mariner and Section Chief of the All-Union Research Institute of Marine Fisheries and Oceanography, Moscow, U.S.S.R., deals with the principle of clockwise rotation of the line of relative motion, as applied to simultaneous encounters with several ships. He presents arguments for a strict compliance with the well known dictum of Captain Oudet: ‘Encounters at sea are governed in such a way that each party knows what he should do and what the other should do.’ The paper was written in collaboration with the late Captain G. Shoomayko.

During the morning of 27 January 1968 the submarine Minerve was on exercise south of Cape Sicie. She was due to return to her base, Toulon, in the evening. Her last-known position was that fixed by a Breguet Atlantic aircraft on the same day at 0735. The last communication between this aircraft (then returning to base) and the submarine was at 0755.

The earliest record of a requirement for ships to carry lights that the author has been able to find is in the Rhodian Laws. These appear to date from about the 3rd or 2nd century B.C., and were certainly incorporated into Roman Law by A.D. 161, although Ashburner suggests that the earliest known copy dates from Byzantine times, A.D. 600–800. The Laws contain a section intended to prevent collisions between vessels under way and vessels at anchor or stopped.

This paper was first published in the Journal in 1969 (Vol. 22, p. 118). It is followed by comments from John Kemp.

The last twenty-one years have seen some very striking advances in our knowledge of how animals can determine their location. In many cases we have learned that they have available a wider range of stimuli than ourselves for recognizing landmarks and for pilotage within their home area. Thus the associated senses of smell and taste are extraordinarily well developed in some species. The ability of the males of certain moths to detect the scent emitted by females at very considerable distances had long been known. More recently the extreme sensitivity, and selectivity, of fish to waterborne odours has led to an understanding of how they locate their home waters. As but one example, eels have shown reactions to concentrations of chemicals as low as 3 × 10−18, equivalent to but two or three molecules within the fish's olfactory sac. In other cases animals have developed sensitivities of which we have little or no conception. Ecolocation is employed by certain birds, by many marine animals and reaches a peak of efficiency in the case of bats. Not only do the latter detect sounds of much higher frequency than ourselves, they also respond to echoes of sounds they emitted but 0·001 seconds earlier. We have little appreciation of the sensations produced by the pressure-receptors in the lateral-line organs of fish.

This paper is concerned with the legislative change which would have to take place if an automatic collision avoidance system were to be implemented.

The principle of complementary action, and the role of coordination in achieving that action is considered. Current collision avoidance practice is discussed, noting the coordination attributes of the International Regulations for the Prevention of Collision at Sea, and the responsibility placed on the mariner by the regulations. The processing element of an automatic collision avoidance system is considered in the light of current judicial practice.

The paper concludes that the implementation of an automatic collision avoidance system is incompatible with the current collision regulations and the supporting judiciary. It is suggested that successful implementation will require the recognition of a discrete rule base.

The AN/SSN-6 Navigation Sensor System Interface (NAVSSI) Project is a new system being designed with two primary objectives; to serve as the central distribution computer for navigation data to shipboard combat/weapon systems and to serve as the electronic chart display and information system (ECDIS). The NAVSSI will operate the digital nautical chart (DNC) database being developed by the Defense Mapping Agency (DMA). Our goal is for the digital nautical chart to replace the paper chart as a legal means of ownship navigation plotting. This paper will introduce the project and will primarily explore the use of digital nautical charts for ownship navigation with NAVSSI.

The integration of magnetometers and Inertial Navigation Systems (INS) is widely used in low-cost navigation systems. However, even if the system has been calibrated, random magnetic disturbances still appear in practical applications, which lead to large heading errors. To solve this problem, an adaptive anti-disturbance method to overcome random magnetic disturbance is proposed. First, disturbances are classified and analysed in detail based on actual road vehicle driving data. Then an Adaptive Robust Extend Kalman Filter (AREKF) is designed to resist sudden disturbances. However, an AREKF may accumulate errors slowly when a long-term disturbance exists. Considering this situation, this paper proposes that AREKF is used to maintain accuracy in the early stages, at the same time as the magnetometer is quickly calibrated with a Kalman filter. Then, the new magnetometer parameters are put into the AREKF to suppress long-term disturbances. Finally, cascading these two modules, not only the sudden disturbance can be overcome, but the situation of long-term disturbances can be suppressed. The results of simulation and an actual driving test show that the proposed method can effectively overcome random magnetic disturbances in both the short and long term.

This paper represents a follow-up of work previously reported at an Ordinary Meeting of the Institute and published in the Journal in May 1986 under the title ‘Navigational Aspects of JTIDS’.

Technical studies on JTIDS for the airborne applications are being directed by the Royal Aircraft Establishment (RAE), Farnborough and by the Admiralty Research Establishment (ARE), Portsdown, for maritime use, for which Systems Designers Scientific is providing technical support in a number of areas. One such field is Relative Navigation (relnav). As part of this MOD-funded work a relnav simulator has been developed at the RAE. This simulator is currently in use for the assessment of the relnav capability and has been used to produce the results presented in following sections.

This report gives a brief description of JTIDS relnav and presents some basic features of relnav performance in simple communities. Then a description of relnav performance in fragmented and loosely coupled communities is presented. Finally a brief summary of the main points and conclusions is given.

This paper discusses the design, development and operation of two tools intended for B-RNAV operations: the enhanced AUGUR system, which was commissioned by EUROCONTROL, and the Global Positioning System (GPS) Performance Monitoring System (GPMS), commissioned by National Air Traffic Services Ltd. (NATS). Both tools were implemented by STASYS Ltd., with support from Delft University on AUGUR algorithm issues. AUGUR, a Predictive GPS Receiver Autonomous Integrity Monitoring (RAIM) system, performs complex calculations and provides an easy-to-interpret Internet-based interface to aid aircraft operators with the use of GPS. Enhancements to AUGUR have been implemented to meet user requests and the requirements of a future Joint Aviation Authorities (JAA) Temporary Guidance Leaflet (TGL) on the airworthiness and operational approval for the use of Area Navigation (RNAV) systems in European airspace designated for Precision RNAV (P-RNAV) operations. The GPMS records output from a variety of GPS UE, has a real-time interface, performs simulations based on logged data, and permits remote analysis. The work carried out consisted of specifying a system to meet the safety study recommendations, choosing hardware, analysing interface requirements, and developing systems and software. These tools are now in place to help with GPS B-RNAV operations, and provide a layer of safety for both en-route flight and GPS-based non-precision approach operations in European airspace.

We present a method of teaching the basics of celestial navigation, using the Javascript programming interface to Google Maps. This offers the teacher of celestial navigation many highly visual and flexible investigative and presentation options, all using the familiar Google Map system. In this paper, we discuss the programming route to Google Maps, and demonstrate an exercise of correcting the assumed position of a hypothetical lost ship, using sights of the Sun, suitable for classroom use. We also present an analysis of the relationship between the proximity of the assumed to the actual position of the ship, and the outcome of a sight-reduction procedure.

This paper discusses the technical, administrative and certification compatibility issues associated with satellite augmentation of GPS/GLONASS. It indicates that the Signal-in-Space specifications are central to compatibility and interoperability. ICAO Standards and Recommended Practices are a key mechanism for interoperability. The paper recommends that one standard be implemented worldwide. It also urges a mechanism for the co-ordination and management of augmentation services.

Time and space scales are compared for selected speeds of ships in the North Atlantic and North Pacific oceans. Viability of westbound passages on some northern great circle routes is discussed.

There would be no problem in precisely weather routing a vessel across an ocean if it were possible to forecast with total accuracy the actual sea state existing for the duration of a voyage. All mariners are well aware that such an ideal circumstance is not as yet possible. Depending upon the general synoptic situation existing for the period, it is fair to make the assumption that the actual accuracy of a weather forecast deteriorates as time progresses.

Training courses on marine radar simulators are held in this country at the Navigation Schools and Colleges in London, South Shields, Hull, Glasgow, Liverpool and Cardiff, with Southampton starting at some future date. The entry for each five-day course is limited to six members and places on the courses are at present generally restricted to serving masters and chief officers. The purpose of these courses is to give seagoing masters and senior officers realistic practice in manœuvring their vessels by radar in conditions of bad visibility without any of the risk involved in an actual encounter between vessels at sea, as well as risk-free opportunity to try out and test the different methods of radar presentation and plotting.