This paper was presented at the World Congress of the International Association of Institutes of Navigation (IAIN) held in Amsterdam, The Netherlands, 17–21 November 1997.

Remote, or shore-based, pilotage means different things to different people, despite a definition being produced by the European and International Maritime Pilots Associations. The debate about it is set in the context of increasing public awareness of the environment and a downward pressure on costs; these in themselves make for uncomfortable bedfellows. However, this sets the scene for the current aspirations within the European Union for vessel traffic management and the ongoing research into Vessel Traffic Services (VTS) and Vessel Traffic Management and Information Services (VTMIS). The technology to implement navigational assistance of a fairly high order is already in place, but there are still problems to be overcome before the concept can be taken further. Commonly recurring concerns over remote pilotage are the inadequacies of radar, difficulties with language, lack of ‘feel’ for the ship, which includes the on-board pilot's assessment of the quality of the vessel's crew, and the lack of ship motion data. Differential GPS is now capable of aiding automatic docking of some specialized vessels, but it has emerged, most recently at the IALA VTS Committee meeting, that ECDIS has shortcomings when being considered as the geographic information system of a VTS. Transponders are the subject of yet another debate, but will the data that they can convey be able to replace an on-board pilot?

This paper considers the issue of operating aircraft through the North Atlantic's Minimum Navigation Performance Specification (MNPS) airspace. Noting that aircraft constantly strive for reduced fuel burn and uplift, it describes how flight operators and pilots conduct safe, efficient flights through the region. Reference is made to mechanisms of the North Atlantic MNPS airspace in terms of its Organized Track Structure and other routes that exist. These different structures emphasize the level of flexibility available. Flight planning procedures and requirements necessary to obtain oceanic Air Traffic Control (ATC) clearances are mentioned, as is an account of how communication and position reporting procedures operate to apply the Mach Number technique. Other aspects of MNPS operations such as ETOPS operational restrictions, meteorological effects, the employment of Reduced Vertical Separation Minima and planned regional changes aim to provide an overview of the MNPS system's current and future air traffic management.

Digital Selective Calling (DSC) is causing serious problems for Search and Rescue (SAR) providers. Administrations must seriously consider the humanitarian and legal implications of continuing the implementation of DSC. They may be in violation of the Safety of Life at Sea Convention, the International Convention on Maritime Search and Rescue, 1979, and the United Nations Convention on the Law of the Sea, 1982, by knowingly implementing communications technology that may jeopardize lives at sea even though the primary intent of DSC is to establish a suitable distress alerting method. States may very well open themselves to legal liability if loss of life or environmental damage can be linked in any way to the known faults of DSC.

Recent developments in remote imaging equipment carried on satellites have given the scientific community a vast amount of new information about the Sun and its atmosphere. Media coverage of the remarkable discoveries accompanied by impressive images of the Sun's atmosphere, and linkage to the loss of a television satellite over the United States, have focused public attention on the existence and effects of the Solar Wind. This paper sets out to illustrate the impact of the Solar Wind on radio aids to navigation, and to look at the possible effects on present and proposed systems.

This paper is based on the results of the ‘GNSS Support Task’ study for the European Commission, DGXIII. It summarises the results of the cost benefit analysis in terms of coverage, accuracy and safety requirements for different types of user and describes the most cost-effective GNSS 2 architecture. These analyses also assume that the overall system is layered into wide area, regional and local systems. The future planning of satellite navigation is essentially driven by the wide area requirements and ensuring that these are global and seamless. There is some flexibility in coverage and accuracy for a wide area system in that it can be augmented regionally or locally if required, but it must provide the highest level of safety required. The paper approaches the architecture for a future navigation system from this safety aspect. An analysis of the chosen architecture shows that the required safety performance can be met. An implementation plan is described which allows a gradual evolution from the first system to be realized for safety critical operations to a fully civilian owned and operated system.

This paper, and the paper which follows it, were first presented at the IBC '98 Conference ‘Space-Based Navigation Industry’, which was held in London, 11–12 June 1998.

In conventional arable agriculture, position within the field was usually irrelevant! However, the advent of precision agriculture, wherein inputs are targeted according to locally-determined requirements within the field, has opened up a potentially large market for GPS. Indeed, it was the availability of GPS which permitted the development and implementation of precision agriculture – a concept which holds the promise of significant economic and environmental benefits to the farmer. This paper indicates the technical requirements for GPS and presents three case studies where a positioning system is required.

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.

Over the last few years, on-the-fly integer ambiguity resolution for GPS has proven to be successful over short baselines (<20 km). However, the remaining challenge has been to extend the length of the baseline between the reference station and the mobile receiver, whilst still maintaining the capability of on-the-fly resolution and true carrier-based kinematic positioning. The goal has been to achieve centimetric level positioning at ranges of over 500 km. New techniques have been developed at the University of Nottingham to allow very long baseline integer ambiguity resolution, on-the-fly. A major problem with the use of carrier phase data is that posed by cycle slips. A technique for detecting and correcting cycle slips has been developed, and its use is discussed in this paper. The new technique has been proven through a series of trials, one of which included two flights to the North Pole, performing centimetric level positioning all the way to the pole. For many years, the GD Aero-Systems Course of the Air Warfare Centre based at RAF Cranwell executed a series of equipment flight trials to the North Pole, called the ARIES Flights. In May 1996, the authors were fortunate to take part in both flights, via Iceland and Greenland, to the North Pole. Based on reference stations at Thule Air Base, integer ambiguity resolution was accomplished, on-the-fly, and centimetric level navigation maintained throughout the flights. Earlier trials detailed in the paper demonstrate that the technique can resolve integer ambiguities on-the-fly within a few seconds over a baseline length of approximately 134 km, resulting in an accuracy of 12 cm. The majority of the residual error source for this being the ionosphere.

The complex and far-from-intuitive issue of establishing how and when to act when manoeuvres are to be performed in space is discussed here in a simple graphical way. An analysis was made of the effects on the parameters of an orbit of low thrusts in three directions: tangential to the orbit; normal to it in the orbit plane; and normal to the orbit plane. An outcome is that, in order to obtain a desired effect, and at the same time minimize the undesired ones, it is better to use only a tangential thrust or only a normal one rather than a combination of simultaneous tangential and normal thrusts. Thus it is not necessary to investigate any alternative orientation of the thrusters. A manoeuvre can be accomplished by thrusts given either only once along the orbit path, or in more than one orbital point. Diagrams are produced which give a quick insight into the manoeuvre philosophy for both kinds of action.

The objective of this paper is to illustrate a methodology for the enhancement of meteorological marine forecasts tailored to the needs of navigation. The study consists of two parts: (1) Theoretical background. Introduction to numerical models for weather forecasting used by meteorological centres. A review of the most reliable equations for prediction of intensity and direction of wind and sea state. In particular, reference is made to the tables for wind forecasting developed by R. Mayençon and A. Pezzoli and the equations for prediction of sea state obtained by K. Haselman and D. J. T. Carter in light of the JONSWAP experiment. (2) Practical application. Application of the methodology to a real-world example: a weather forecast elaborated by the Meteohydrological Laboratory at Dipartimento d'Idraulica Trasporti ed Infrastrutture Civili (DITIC) of the Polytechnic of Turin. The forecast was requested by the Consorzio Prada Challenge 2000 as a meteorological support for the training they held in the Tyrrhenian Sea for the next America's Cup series.

The content of this paper was presented at the International Maritime Association of the Mediterranean, 8th International Congress on Marine Technology in Istanbul, November 1997.

The effect of different measurement points on an acquired target is theoretically investigated with respect to the ARPA plotting performance. The target is described by simple geometrical figures and the echo is simplified. The actual measurement position is generally not at the centre of the target. This may cause errors in the standard plotting results. The characteristics of these errors are discussed from a nautical viewpoint.

Global Positioning Systems (GPS) are now in use in many applications, ranging from GIS to route guidance, automatic vehicle location (AVL), air, land, and marine navigation, and many other transportation and geographical based applications. In many applications, the GPS receiver is connected to some form of intelligent electronic system which receives the positional data from the GPS unit and then performs the required operation. When developing and testing GPS-based systems, one of the problems is that it is usually necessary to create GPS-compatible geographical data to simulate a GPS operation in real time. This paper provides the details of a Personal Computer (PC)-based GPS simulator system called GPSIM. The system receives user way-points and routes from Windows-based screen forms and then simulates a GPS operation in real time by generating most of the commonly used GPS sentences. The user-specified waypoints are divided into a number of small segments, each segment specifying a small distance in the direction of the original waypoint. The GPS sentence corresponding to the geographical coordinates of each segment is then sent out of the PC serial port. The system described is an invaluable testing tool for GPS-based system developers and also for people training to learn to use GPS-based products.

Anticipating that transport on the West European inland waterways will increase in volume, in ship size and in speed, experiments are being carried out to investigate whether safety of navigation – including traffic management – can be improved by the employment of GPS or DGPS, electronic navigation charts, river radar and computer technology. Although waypoint navigation and collision avoidance systems are generally accepted in the maritime world, these methods could cause problems when applied on inland waterways.

For most ship navigators, this discussion is now purely academic – which does not make it less interesting.

This paper was presented at the Third Electronic Chart Technology Conference, SASMEX International, Brighton, 22–23 April 1998.

Electronic Chart Systems have been used by mariners across the entire user spectrum without official standards or specifications for 10 years. In the last three years, the debate has centred on chart data and the merits of differing cartographic technologies. There is little new that can be said for or against raster or vector technologies except what actual users might say to support the requirements of their day-to-day operations. Today, we approach a new stage as ENCs start to become available but only for limited areas. This in turn means that ENCs are capable of supporting the only approved electronic chart system, ECDIS, in a limited way. There is an urgent need for alternatives to ECDIS to cover those areas where ENCs will continue to be unavailable for the foreseeable future. This paper therefore summarizes a feedback from users of RCDS and ECDIS-type systems to demonstrate the benefits which can be secured from official recognition of RCDS systems as the legal equivalent of paper chart navigation.