The rates of collision and stranding at sea are very high. The primary causes of stranding are: not checking a ship's position, inadequate route planning, operational misjudgement and inefficient watchkeeping. These causes are responsible for 90 percent of strandings according to accident statistics. Reduction in stranding risk would be of considerable economic benefit and would also reduce pollution and be welcomed by shipping companies and, of course, by crews.

Criteria and a methodology for evaluating the relative effectiveness of different navigation aids in a coastal region, taking account of the ship-borne equipment, human factors and the needs of the navigator, have been discussed in the Nautical Institute' recently-published book on Pilotage and Shiphandling. The method is based on the product of the probabilities that the equipment will be fitted, that it will be available (in reliability terms), that it will be properly used and that it will provide the required information.

In this paper, the authors discuss a fully automatic berthing system and actual tests using a small training ship, Shioji Maru. The ship is about 440 gross tonnage and furnished with a controllable pitch propeller, a bow thruster and a stern thruster to which a computer can easily be linked. The system developed is composed of an electro-optical position measuring system and the computer software necessary for manoeuvring the ship.

The electro-optical position measuring system can measure a distance between the ship and a target on a berth within 4 cm accuracy and cover an area out to about 100 m range. The manoeuvring is divided into two stages. The first one is from a start line to a transition point off the final berth. At this point, the ship must be stopped in an alongside attitude to the berth. In the second stage, the ship is pushed by the thrusters in an athwartships direction towards the berth and the final speed at the berth must be limited to within 0.5 ms. The computer software generates an appropriate strategy following an approach line which has been determined in advance.

According to the actual tests under slightly rough sea conditions, the system could manoeuvre the ship along the approach line by a direct path and maintain her final speed within the predetermined limit.

The mobile radio communications industry has recently witnessed a new demand for terminal equipment which can provide both communications and position reporting capabilities on a global scale–for example, the automatic monitoring of secure cargoes during international transportation. Thus, there is much interest in the development of land mobile satellite terminal equipment in the form of a single integrated unit which can economically provide both of these facilities. In this paper the development of such a unit is considered using the Inmarsat-c satellite communications service and the Navstar Global Positioning System (GPS), with extension to GLONASS possible in a receive-only version.

This paper was presented at the Institutes NAV90 Conference but was received too late for inclusion in the Proceedings. Copies of the Proceedings are available on application to the Director.

The following two papers were presented at a joint Royal Aeronautical Society/Royal Institute of Navigation conference on ‘European Navigation into the 21st Century’ on Tuesday 12 February 1991.

The existing system of point-source radio navigation aids deployed throughout the European Region (e.g. VOR, DME, NDB), is inherently inflexible and suffers from a number of problems which degrade its efficiency; providing little scope for route capacity expansion. Area Navigation (RNAV) is seen to offer the answer to many of these deficiencies. Many aircraft are already fitted with RNAV – a system of navigation that allows track maintenance to defined levels of accuracy without the need to overfly point source aids. However, the full benefits of RNAV, including the introduction of more direct fuel efficient routes, arrivals and departures, and substantial increases in route capacities made possible by the application of reduced lateral and vertical separation criteria, cannot be fully realized until virtually all aircraft are equipped to a precision RNAV standard, and minimum aircraft systems performance specifications are introduced. This is unlikely to be practicable before 1998.

Timescales have been established for the progressive implementation of RNAV capability. High levels of cooperation between European states should ensure that operational implementation is achieved in a coordinated, efficient, orderly and safe manner. Certification and operational standards are being developed jointly and European guidance material, developed under the auspices of ICAO, is soon to be adopted by ICAO RGCSP for global application. Appropriate legislative amendments are being developed in the United Kingdom and elsewhere in Europe. All the present indications are that the implementation of RNAV in Europe will proceed successfully on an evolutionary basis, between now and the turn of the century.

For a long time it has been accepted as fact that at least certain animals, such as birds and honey bees, have an in-built sense of orientation which enables them to find their way home. Less well-known examples occur among the molluscs and amphibians.

For the foreseeable future, and despite a forecast reduction in the amount of activity, military flying will continue to embrace the diverse requirements of low, medium, and high-level route navigation, as well as the less structured, but more demanding, tactical navigation, principally carried out at low-level. As East-West relations have improved, defence budgets have come under increasing pressure and, whereas military projects have been in the vanguard of navigation system development in the past, the stagnation of military flying rates has been overshadowed by a dramatic expansion in the commercial sector. Consequently, the balance has shifted and many developments in all spheres of navigation are now led by civil requirements. Nevertheless, there continues to be close cooperation within NATO, with nations attempting to keep in step with each other and with international developments.

Increased fuel costs necessitate a careful consideration of consumption when planning voyages trans-ocean. A model is formulated whereby ship response algorithms are matched with forecast environmental conditions expected for the duration of a voyage. A discrete system allows an optimization routine to minimize fuel costs for a trans-atlantic passage, using dynamic programming techniques.

These are simulated by using an on-board boosted micro-computer. The results are discussed and limitations of the system considered.

This paper describes the basic principles of a method developed to guide aircraft accurately down to the runway in a time-of-arrival constrained environment. The method is designed to be used in a ‘zone of convergence’ context or in any similar advanced air traffic control system characterized by the integration of control phases over an extended area on the one hand and true ‘computer assistance’ to the air traffic controller on the other; that is, assistance provided at the decision-making level through the automatic generation of guidance advisories.

The method includes two closely-coupled basic components; namely, a ‘predictor’, which computes a trajectory once initial conditions and plans are known, and a ‘profile manager’, which adapts the plans to meet the time constraints and generates the guidance directives on the basis of present position, actual surveillance information, aircraft operation and route constraints.

This paper was presented at an RIN meeting on ‘Air and Marine Radar Developments’ on Wednesday 16 January 1991.

During the last decade there have been significant developments in the civil marine radar field, resulting in: (1) Improved radar detection performance; (2) Improved operational facilities; (3) Improved reliability; (4) High brightness, daylight viewing, colour and monochrome displays with full ARPA performance; (5) Integrated radar and navigation systems; (6) Reduction in costs.

In this paper, the methods of collision avoidance by radar which have been used in the radar simulator course at Chinese marine colleges are introduced. Then some other methods of estimating the risk of collision, safe passing distance and course alteration in radar collision avoidance are presented.

This paper is one of four presented at a joint meeting with the Honourable Company of Master Mariners on 17 April 1991.

A Long-range Secondary Surveillance Radar (LSSR) has been developed and recently used as an Oceanic Route Surveillance Radar (ORSR) in Japan. The LSSR is an SSR (Secondary Surveillance Radar) only system for which the maximum coverage is 250 nautical miles (n.m.). This system utilizes monopulse azimuth estimation techniques for improving the accuracy of azimuth estimation.

In this paper some interesting properties of circular orbiting satellites' ground traces are pointed out. It will be shown how such properties are typical of some spherical and plane curves that look like flowers both in their name and shape. In addition, the choice of the best satellite constellations satisfying specific requirements is strongly facilitated by exploiting these properties.

A recent paper by Cox, ten Have and Forrester is planned to be the first of a series describing the work of the European Vertical Studies Sub Group (VSSG) set up under the ICAO panel for review of the general concept of separation. The present paper has no connection with the VSSG work.