This paper is based on the President's Invitational Address given by the author at the 54th Annual General Meeting on 25 October 2000.

The paper outlines the changes in the physical form in which hydrographic information has reached the chart tables of ordinary navigators over the last five hundred years and traces its development from a purely verbal aid to a graphic one.

The widespread commercial availability of location-based services depends upon every new mobile phone including positioning capability. The timescales for the introduction of these devices is far from clear, and yet the demand for high accuracy services is already increasing, particularly in the automotive and telematics sector. This paper presents a summary of the current and emerging positioning technologies, their capability, predicted timescales and their suitability for the in-car environment. Will GPS levels of accuracy be available in the mobile phone? Who are the various commercial players that may affect the ultimate choice of technology? Have new satellite services such as Galileo left it too late? The paper attempts to answer these and other questions whilst offering an insight into the convergence of satellite and cellular positioning.

This, and the following three papers, were first presented at GNSS 2000, the Third European Symposium on Global Navigation Satellite Systems held in Edinburgh, Scotland from 1st to 4th May 2000.

GNSS, or more specifically, Satellite Based Augmentation System (SBAS), guidance provides the prospect of a low-cost means for aircraft to become equipped to fly area navigation (RNAV) operations. The implementation of such RNAV operations within UK airspace offers potential benefits to both the airline operators and the Air Traffic Service Providers (ATSPs).

The ever-increasing number of vehicles on the road has created a serious demand for traffic information not only on the move but also at the planning stage of a journey. While on the move, the driver will be able to re-route his/her journey avoiding traffic congestion, but this information could be even more valuable before starting the journey. Today there are differences between the three main ITS markets (USA, Japan and Europe). Japan is leading the way, with the introduction in 1995 of the Vehicle Information Communication System (VICS), which is a free service. Vehicles are equipped with VICS receivers taking information from a network of road beacons installed on main roads, transmitting traffic flows by infrared rays, wave beacons, and FM multiplex broadcast. Europe has been involved in driver information systems from the early '90s when RDS was developed, which is another free service, and most of the car radios sold in Europe are able to process RDS signals. Since then, new free services have been developed – for example, RDS-TMC. In the UK, the private sector has been heavily involved recently, its major player being Trafficmaster. The Trafficmaster system is based on a network of traffic detection sensors, which covers all major UK motorways and most of the major A roads, with plans to expand into the continent. Trafficmaster collects road traffic flows and disseminates this information to its subscribers via a range of technologies, including GSM. The quality of the information supplied by the free and subscription services can be improved by being fully integrated with on-board navigation systems and by providing more detailed and wider types of information. All current methods are described/analysed and compared in this paper, with future enhancement highlighted. One of the main limitations lies in current data transmission routes, which are not fast enough to support the data required for an optimal use of the system. Some technologies available will potentially allow the many service providers to transmit information.

This and the following paper were first presented at the RIN01 Conference held in Oxford under the auspices of the Animal Navigation Special Interest Group, April 2001.

Flight paths of homing pigeons were measured with a newly developed recorder based on GPS. The device consists of a GPS receiver board, a logging facility, an antenna, a power supply, a DC-DC converter and a casing. It has a weight of 33 grams and works reliably with a sampling rate of 1 Hz for an operating time of about three hours, providing time-indexed data on geographic positions, ground speed and altitude. The devices are fixed to the birds with a harness, and the data are downloaded when the bird is re-captured. The measured flight paths show many details : for example, initial loops flown immediately after release and large detours flown by some pigeons. Three examples of flight paths are presented from a release site 17·3 km northeast of the home loft in Frankfurt. Mean speed in flight, duration of breaks and total length of the flight path were calculated. The pigeons chose different routes and have different individual tendencies to fly loops over the village close to the release site.

An integrated GPS/GLONASS system was employed in this study to support the re-design of road networks and the adjustment of traffic control. The system was used to update road maps, and to determine the velocity and acceleration of a test vehicle. The vehicle ran along the traffic stream at designated times of a day, for specific time spans, to identify traffic conditions in urban areas of uncontrolled intersections such as roundabouts. Issues addressed included: transformation of GLONASS satellite coordinates from PZ-90 to WGS-84, the presence of the receiver clock error in the GLONASS double-differenced measurements, and the impact of the carrier wavelength variation on the ambiguity resolution. Two tests were carried out in an urban environment using the combined GPS/GLONASS system. The first test included updating a road map of a test area by an RTK approach. Results were checked by comparing them with an accurate map of the area, previously determined by conventional methods. The second test comprised determining position, velocity and acceleration of a moving vehicle representing the traffic flow for a selected area. Different solution schemes were investigated, including: RTK, DGPS, and post-processing of phase measurements. The impact of GLONASS augmentation and the quality of GPS satellites on solution feasibility and accuracy were also examined. Test results showed the benefits of adopting the integrated approach. These included: improving productivity and economics of map production, and improving availability, integrity, and accuracy of determining the velocity and acceleration, linked to positions on the road networks.

This paper describes three different antenna systems for mobile vehicle applications. The antennas are either patches or derivatives in all cases. The first is a dual-band telephone antenna with a low profile and wide bandwidth. Operating at 900 MHz and 1800 MHz, with a VSWR of better than 1·7, it is a hybrid construction combining a monopole with a top-loading patch shorted to the ground-plane. Extra-shorted pins provide the upper frequency band coverage. It provides monopole radiation characteristics and can be hidden under a plastic panel or mounted on the vehicle roof. The second is a microstrip patch antenna integrated into a laminated glass windscreen for a vehicle. It is fed using a coplanar waveguide feed printed on the innermost layer of the glass, avoiding the need for a contacting feed within the laminate. The patch and ground plane are meshed for manufacturing in the glass to avoid distorting the heat profile when the glass is shaped and laminated. The patch is easily fed from inside the vehicle and is potentially a very low cost design. The final antenna discussed is a dual-band patch antenna specifically designed for the Globalstar satellite telephone system at 1·6 GHz and 2·45 GHz. It also covers the Iridium band at 1·6 GHz. A single circularly polarised patch is used. Dual-band operation results from truncating the corners of the square patch and judiciously placed slots to achieve a band spacing of 1·5.

Human wayfinding in the natural environment has been practised for thousands of years. In the urban or built environment, few natural cues are available and other aids to wayfinding are needed. This paper considers the problems of wayfinding in airport terminals, what cues are available and how passengers use them to reach their destinations. The use of signs and maps is discussed, and conclusions are drawn on how wayfinding in airport terminals could be improved.

The principles of wayfinding are simple; the practicalities are very complex.

Nainoa Thompson.

The 11-year solar sunspot cycle is approaching a maximum in 2000. The sunspot activity causes an increase in the solar flux, charged particles and electromagnetic rays emitted from the Sun. This solar flux affects the ionosphere, thus influencing the transmission of radio waves through the ionosphere. The GPS satellite navigation system is affected in that the transit time of the signals varies, introducing position errors. Also GPS equipment may experience degraded performance in tracking of the GPS satellites due to scintillations, rapidly varying amplitude and phase of the GPS signal. The equatorial and high latitude regions are most severely affected by this increased ionospheric activity. Experience has shown that, in equatorial regions, errors of 10–20 m may be introduced in Differential GPS services, even on distances down to a few hundred kilometres from the reference station. During the peak of the solar cycle, for the next 3–4 years, this situation will rather be the rule than the exception in the affected areas. Fugro has introduced an enhanced real-time DGPS service utilising dual frequency GPS called Starfix-Plus in selected areas. This service removes ionospheric delay errors by calculating the delay using dual frequency GPS receivers on the reference stations and the mobiles. The resulting accuracy is down to a few metres, even using reference stations up to 2000 km away. This increases the availability and redundancy of usable reference stations in a region, increasing the probability that the required accuracy is available, even if individual stations are not available due to scintillations or for other reasons.

Within the implementation of the European Geo-stationary Navigation Overlay System (EGNOS), a significant residual error in positioning is due to tropospheric delay effects. The EGNOS guidelines recommend that tropospheric delay is modelled using an empirical correction algorithm based on a receiver's height and estimates of meteorological parameters developed from average and seasonal variation data. However, such a simple average and seasonal variation model is unlikely to emulate temporal weather changes exactly. The potential errors involved in the application of the recommended algorithm and the consequent effects on the positioning errors, under typical UK weather conditions, are detailed in this paper. This was achieved by comparing tropospheric delays produced by the EGNOS model, with tropospheric delays estimated from high precision carrier phase GPS, over a one-year period for five UK stations. The RMS EGNOS model zenith tropospheric delay errors ranged from 4·0 to 4·7 cm, with maximum errors ranging from 13·2 to 17·8 cm. The errors were also shown to be spatially correlated. The subsequent effect on position error is shown to be dependent on the satellite elevation cut-off angle adopted and on whether or not the observations are weighted according to the satellite elevation angle.

This paper presents the results of a research project that investigated the potential benefits of a combined Galileo/GPS navigation system. The research addressed in detail the two key required navigation performance (RNP) parameters of accuracy and integrity. The project was supported by Alcatel Space and was a contribution to the Galileo definition studies (supported by the European Community under the GALA project). The results show significant improvements in both accuracy and integrity (achievable through RAIM) when a combined constellation is used rather than Galileo alone.

Following the publication of the Government's White Paper on Integrated Transport in July 1998, and a shift in emphasis by Local Authorities away from road building to demand management techniques, the current trend is to a more balanced approach, whereby the use of road-space may be charged to vehicle drivers, i.e. road users pay to use (at least some) roads, just as public transport passengers pay each time they travel. Key to this is the introduction of some form of road user charging or vehicle access control. In urban areas, this may be achieved using paper licences (as in Singapore, 1975–1998), electronic (microwave) tags and transponders (as in Trondheim and Oslo, Norway and in Singapore since 1998) or by the use of automatic video-based licence-plate recognition (ALPR). The use of video-based registration to check whether a vehicle has purchased (or been granted) some form of licence rights to use a particular road or cordoned area on a particular day seems both logical and attractive. However, this form of urban road use pricing has not been operated in anything other than small-scale pilot schemes, and there are a significant number of technical, organisational and operational issues that need to be researched before such a system could safely be implemented for everyday use. This paper is specifically aimed at addressing such key issues, to determine whether in the short term (next 5 years) ALPR could deliver a practical tool for use by local authorities, whether in isolation or as part of a package of applications, to reduce traffic congestion within urban areas.

The basic concepts safety at sea and the maritime safety system have remained almost unchanged for a comparatively long time. However, the components and elements of these concepts are now subject to many changes created by the ‘information age’. This paper presents thoughts on today's concept of the maritime safety system, its main components and their elements. Although the thoughts and ideas presented are those of the authors, they take account of the legal instruments in force and recent developments in technology, especially developments in radio-communications. The paper provides an overall review of the institutions, regulations and procedures concerned with safety at sea.

This and the following paper were first presented at NAV 2000 on Thursday, 2 November 2000 – the day devoted to Location and Communication for Land Vehicles.

This paper discusses the need for Intelligent Transport Systems (ITS) and the key factors influencing the Government's Integrated Transport Policy. Typical ITS projects and applications in the UK are reviewed and conclusions drawn.

Navigation map databases have evolved during the last 10 years in coverage, content and accuracy to such a degree that they are being used (and considered) for applications beyond vehicle navigation. For a number of advanced driver assistance systems (ADAS) in Europe and North America, the navigation maps are being enhanced to offer new functions. This will complement dynamic route guidance, with location referencing, descriptions of delays, floating car data and re-routeing, all requiring developments in traffic management, road capacity balancing and routing algorithms.

Radio approval for spectrum management, and vehicle EMC type approval for road safety, are different approvals for different purposes. Modern vehicle applications of radio systems for telematics purposes have resulted in both of these approvals having to be applied to radio systems fitted to vehicles. This paper looks at automotive EMC legislation and its interpretations relating to radio issues. The changes to radio type approval with the implementation of directive 1999/5/EC and the interpretations for automotive systems are discussed.

Earlier papers, based on a computer model of European air traffic, deal with the probability of conflicts arising between pairs of aircraft operating under free-flight rules. This paper discusses the problems of resolving these conflicts. When a potential collision takes place in the neighbourhood of other intruding aircraft, these must be taken into account when choosing an escape manoeuvre. A suggestion is made that may ease the problem.

In December 1999, the European Commission adopted the European ‘Statement of Principles’ (SoP) in acknowledgement of the importance of the human-machine interaction (HMI) for in-vehicle telematics. In recommending adherence to the Statement of Principles, the EC urges the European motor manufacturing and supply industries to comply with a number of basic safety requirements concerning the design of, and driver interaction with, in-vehicle information, communication and entertainment systems. When the SoP was published, Member States were invited to undertake work to assess industry knowledge about, and compliance with, the Statement of Principles. TRL are currently undertaking this work for the UK Government in support of their work to assess the impact of the SoP and develop future policies concerning HMI. This paper discusses the results of a widespread UK consultation with individuals identified as working in the field of in-vehicle information, communication and entertainment systems (IVIS). It also outlines work undertaken to establish a method for assessing the extent to which a specific IVIS complies with the SoP. It describes the development and design of a HMI safety checklist that can provide an initial assessment of whether a specific IVIS is in accordance with the Principles.

This paper describes the rationale used by the Royal Automobile Club (RAC) Motoring Services to update and improve the location and communication systems used by their breakdown service. It discusses the needs and problems of locating customers, and of locating, controlling, and communicating with patrols; the new systems adopted to meet these needs are described. Future requirements are also discussed together with new technologies that are expected to become available.

This paper was first presented at the RIN97 Conference held in Oxford under the auspices of the Animal Navigation Special Interest Group, April 1997.

Migrating species may utilise hydrostatic pressure. In the aquatic environment, hydrostatic pressure changes much more rapidly than in air. In shallow water, tidal changes will impose larger percentage changes on organisms than those experienced in deep water. Small changes in pressure often cause locomotion (barokinesis) accompanied by orientation to light or gravity, often partially compensating for the equivalent depth change. Until recently, identification of hydrostatic pressure receptors without a gas phase has proved elusive, but it is now known that thread hair receptors in the statocyst of the shore crab Carcinus maenas respond to small changes in hydrostatic pressure. Using a tide machine, the responses of thread hairs to sinusoidally changing pressure cycles have been examined, and this paper reports progress monitoring this receptor and making long-term recordings from hydrostatic pressure sensitive pathways in the crab's nervous system.