The paper is mainly concerned with the principles used by TCAS (Traffic alert and Collision Avoidance System) to resolve conflicts between airborne aircraft. It leans heavily on an earlier paper which describes the threat-detection process. The simulation results given were obtained using a fast-time computer model for random traffic and comprise statistics on miss distance, warning time, etc., for a simple traffic pattern.

This is an abridged version of a paper which was presented at the NAVIGOS Seminar held in Cairo in October 1986. It describes the development of ship routeing in the Gulf of Suez since 197J. Dr Mokhtar is Director General of the Arab Maritime Transport Academy and Commodore Hussein is a consultant at the same Academy.

Omega is one of a wide range of navigational aids that have been developed and are in everyday use by ships and aircraft. By contrast, outside the military field as yet there has been no significant application of these aids to mobile land vehicles. The reason has been a mismatch between the perceived accuracy requirements of the potential user, what he is prepared to pay, and what technology could provide.

This paper formed the 1987 Anderson Memorial Lecture, and was presented to the Bristol Channel branch on 24 March.

A decade ago the opinion was expressed in that authoritative work The Use of Radar at Sea that:

In its peaceful application marine radar is hardly out of its adolescence. In twenty years it may have grown out of recognition. Whether it does so or not depends upon a number of factors of which, perhaps, the most important is progressive thought on the part of the user and his employers (p. 258).

There are now radar installations which track ships automatically, and these radars can provide the researcher with statistics on collision-avoidance manoeuvres. The extraction, by hand, is laborious and time consuming. This paper describes a mathematical model which automatically detects collision-avoidance manoeuvres. The model operates on an adaption of the Range to Domain Over Range Rate (RDRR) principle, which enables ships to be identified for analysis shortly before they are expected to initiate a collision-avoidance manoeuvre. The model has been computerized and results presented.

A review of the nuclear magnetic resonance gyroscope (NMRG) as a rotation-rate sensor is presented. Most of the activity in the recent past on NMRG research originated in the USA and concentrated almost exclusively on forms of the NMRG utilizing optical-pumping techniques. To date, only the National Air Defence Centre at Warminster, Pennsylvania continues to pursue a low-cost variant of the NMRG while in the UK, only ARE (Slough) and Sussex University remain active in NMRG research. The emphasis on activity in the Navigation Division at ARE (Slough) has continued to be on cryogenic helium-3 (3He) techniques and the use of superconducting shielding (although optical-pumping will also be pursued). The continuing incentive for NMRG research remains the requirement for a ship's low-cost inertial navigation system (SLINS).

This paper describes the application of navigational ideas during a late stage of the Yorkshire Ripper investigation. The conclusions reached were irrevocably recorded before the ultimate facts were established by the arrest and conviction of the killer. The reader is invited to assess the degree of success of the method and to rework the data supplied according to his own navigational ideas. The suggestion is made that navigational concepts may become a valuable weapon in the field of crime investigation.

This is a short summary of a paper which shows what a navigator can do to fix his position at sea using basic equipment (sextant, hand-held compass, almanac, four-figure mathematical tables) without the help of dead reckoning or the benefits of GMT.

Barring electronics and steady timekeepers the Moon's orbit provides the readiest means of finding Greenwich time at sea. But the Moon moves so slowly in her monthly circuit that an error of only 1′ in locating her will cause an error of nearly 2 minutes in GMT. Obviously the navigator needs some idea of how well he has pinpointed her. Even a modest error, unless suspected and allowed for, could be disastrous.

This paper was presented by W. Blanchard to a meeting of the Technical Committee on 25 March 1987. It has been forwarded to an IAIN Working Party set up to consider possible contributions to the ICAO Future Air Navigation Systems study.