The Eva G. R. Taylor Lecture is jointly sponsored by the Institute with the Royal Geographical Society, the Hakluyt Society and the Society for Nautical Research to enable a lecture to be given every year by a distinguished scholar in one or other of the branches of knowledge to which Professor Taylor made such notable contributions. The 1999 lecture was presented at a meeting held at the Royal Geographical Society on 30 November 1999. Michael Richey first describes the events leading up to the dramatic announcement by Yale University in 1974 that the famous Vinland Map it had acquired some nine years before might well be a fake; and then the steps taken to try to rehabilitate it. Professor Taylor was almost certainly the first scholar to set down in detail the reasons for believing the map to be a forgery. The map remains a mystery, for while the evidence seems for the most part to point towards forgery, who by and when and why remain in the air. Michael Richey is a Gold Medallist and a former Director of the Institute.

This, and the following four papers, were first presented at the NAV99/ILA28 Conference on ‘Loran-C, Satellite and Integrated Systems for the 21st Century’ held at Church House, Westminster, London, 1st–3rd November 1999.

Just 25 years ago, the author presented a paper at the 30th Annual Meeting of the United States Institute of Navigation (ION) entitled ‘Radionavigation in North America, the Next 25 Years’. The paper received much attention and was given the ION's Burka Award for the best paper of the year. The author attempted to predict the worldwide implementation of Loran-C and Omega while acknowledging that satellite technology was on the horizon. ‘Global Radionavigation – The Next 50 Years and Beyond’ builds on the previous paper and is an attempt to define the future of global radionavigation based upon a mix of terrestrial and satellite systems. The time it takes for satellite systems and augmentations to mature and the reasons for this extended period provide the foundation of the paper. Also discussed are: the time to achieve a full constellation of space vehicles having signal specifications that meet the requirements for safety-of-life, the political complexities to achieve international harmonisation of service, and the use of a common worldwide protected frequency spectrum. The need for terrestrial complements is presented from the standpoint of supporting satellite systems and as a back-up in the event of loss of satellite services.

There has been much discussion recently implying that Loran-C chain synchronisation using ‘System Area Monitor’ (SAM) control and using ‘Time of Transmission (or Emission)’ (TOT or TOE) are incompatible mechanisations of Loran-C chain time management because of their differing impact on users. Further, the mechanisation of UTC synchronisation is described as either satellite (GPS/GLONASS) based or Loran Chain measurement based, thereby excluding integrated use of both techniques for reliability. These differences are not mutually exclusive. Well-defined chain synchronisation can logically apply all measurement and control techniques as well as providing improved accuracy. This paper defines synchronisation and describes the history of Loran-C synchronisation control and the current methods employed. The existence of Cesium Standards at Loran stations, and the recent introduction of digital signal processing receivers, have greatly changed the potential for extremely precise timing control, detection of extraordinary timing changes, and the maintenance of very tight UTC synchronisation. This paper describes a number of techniques for defining, observing and applying the various sources of timing information, optimising performance for users and simplifying implementation for service providers.

Loran-C receivers measure time delay differences in the signals they receive, compute differences of distance, and hence determine the user's position. The conversion from time to distance requires knowledge of the signals' velocities, which differ when propagating over sea or land. Precise positioning requires the delays of land paths to be accurately mapped, a procedure traditionally entailing expensive and time-consuming marine surveys. The resulting data, in the form of Additional Secondary Factors (ASFs), may be stored in Loran receivers. This paper introduces the concept of Loran-C Additional Secondary Factors, and shows how it is possible to map them efficiently. It focuses on recent advances, chiefly the development of powerful software for modelling the growth of ASFs over mountainous terrain. This employs an implementation of an algorithm proposed by Monteath. The modelling capability of the algorithm is demonstrated by examining propagation along a route that crosses mountains and deep fjords. In addition, the ASFs it predicts are compared with sample measurements made around the west coast of Scotland.

This paper presents an integrated INS (Inertial Navigation System) and camera-based navigation system. The camera-based navigation system provides position measurement aiding to the INS. This is an alternative to the more conventional GPS (Global Positioning System) aided INS. The system is intended for UAVs (Unmanned Aerial Vehicles) and long-range missiles. The basic principles of camera-based navigation are presented. The Kalman filter based integration of INS and camera-based navigation is discussed. Total system simulation results are shown together with INS simulations for comparison. Finally, a brief overview of factors that improve the navigation accuracy is presented.

Inertial measurement technology can make a valuable contribution to the development of autonomous, sole-means Satellite Navigation Systems. The integration of inertial measurement technology and GPS can enable a significant performance improvement to the various configurations of GPS, WAAS and LAAS. This paper provides a conceptual discussion of the safety and performance benefits that inertial measurement and integration technology can bring to the satellite navigation environment.

This, and the following three papers, where first presented at GNSS 99, the Second European Symposium on Global Navigation Satellite Systems held in Genoa, Italy from 5th to 8th October 1999.

Galileo is being developed as the European contribution to the next generation of navigation satellites to replace GNSS1. Sponsored by the European Union, Galileo will be a civil, internationally controlled and operated system that will secure the long-term availability of satellite-based navigation services for multi-modal purposes throughout the European region and beyond. Galileo will be designed to support a wide variety of applications. These include professional navigation, position reference, safety, emergency, tracking, sport/leisure and governmental. Such services may be open to all, for safety-of-life applications, or for commercial users. In the case of safety and commercial applications in particular, it is imperative that the appropriate institutional control and regulatory framework is in place for purposes of safety and economic regulation. To ensure that the various parties understand their obligations and liabilities, clear legal instruments must be put in place to support the organisational framework. It is planned to attract private investment to fund elements of system development and operation through Private/Public Partnership arrangements. At present there is no institutional, regulatory or legal framework that will enable the early impetus to Galileo development to be maintained. This presents a challenge that Europe must address without delay. It has been the subject of several European Commission studies in the past twelve months. In a complementary activity under contract to the European Space Agency (ESA), a European industry consortium comprising Alcatel, Alenia, DASA and Matra Marconi Space was tasked to complete the preliminary design of the space and ground segments by the Autumn of 1999. One task of this study, led by Matra Marconi Space, relates to a study of the impact of institutional, regulatory and legal issues on the organisation and development of Galileo. This paper describes the studies undertaken into these issues within the overall Galileo development programme.

Satellite navigation has demonstrated its ability to enhance the safety and efficiency of multi-modal transport systems and act as a stimulant to economic growth and commercial development. The decision of the Transport Ministers to proceed with the definition stage of Galileo currently being funded by the European Commission and the ESA GalileoSat programme will include the complex question of security and defence considerations. Initial studies were completed over the past year in a Civil Military Interface study and by the GNSS Forum for Security and Defence Considerations. This paper presents the findings of the Civil Military Interface study undertaken for the European Commission, DGVII, that identified the security and military implications of a civil operated and controlled satellite navigation service for Europe.

Integration of GPS/INS navigation systems is a common topic for aeronautical and road applications. The use of these technologies for personal localisation requires more than just portable sensors and a change of ergonomics; it requires a totally different approach for dead reckoning algorithms. This paper will focus on different human applications and reveals the particular problem encountered.

While position integrity is crucial when positioning systems are to be used for safety-critical operations such as in aviation applications, current positioning algorithms are generally optimised for accuracy instead. Even when they are combined with fault detection and exclusion schemes, these algorithms still give sub-optimal integrity. This paper promotes a new method of algorithm design that takes integrity rather than accuracy as the parameter to optimise. The new class of high-integrity positioning algorithms described aims to improve integrity with both current and new systems not by improving the physical infrastructure, but by using clever algorithmic optimisation in the receiver. A small simulation example shows that the integrity and availability of un-augmented GPS for non-precision approach can indeed be improved substantially.

This paper was first presented at a workshop arranged by the Netherlands Institute of Navigation on 5 November 1999 at the Delft University of Technology, The Netherlands.

The development and introduction of GPS in the early Eighties has led to an exponential growth in military and civilian applications. Worldwide, GPS is becoming a cornerstone in applications of transport, (offshore) survey, (precision) agriculture, network timing, military operations and many other applications. And yet, for a number of applications, GPS as sole-means or augmented – has some deficiencies, and its performance does not satisfy the user's requirements. Some of these deficiencies will be discussed in this paper. A number of maritime operations will be mentioned where (D)GPS as sole-means is considered by the author as unsafe navigational practice. Development and implementation of integrated navigation receivers using multiple navigation-signal sensors ((D)Galileo, (D)GPS, Eurofix, DR) using receiver autonomous integrity monitoring (RAIM) could solve the majority of the deficiencies of these systems in their stand-alone state.

There is increasing pressure from commercial interests to obtain radio bandwidth for both terrestrial and satellite radio-communication applications. Existing civil radio-navigation and military radio-location bands are now being scrutinised by these interests. This background paper is about those pressures and the factors that marine navigators need to be aware of now and will need to deal with in the future.

Four manuscript charts of British ports, and notes on them, were made in the 1590s by an English Catholic pilot, N. Lambert. They were sent to Don Juan de Idiáquez, Philip II's secretary, through the mediation of an English Jesuit exile, Robert Persons (or Parsons). Lambert also offered to pilot Spanish ships and guide Spanish troops in raids on the coasts of England and Wales, and prepared a list of appropriate targets. Being some of the earliest charts of the ports concerned, and hitherto unpublished, they are here presented with relevant background material.

This is an updated and revised version of a paper originally presented to a CNS/ATM Forum of representatives from the States, airlines and air traffic service provider organisations of the Pacific region meeting in Sydney, Australia on 16 April 1998. The Forum was organised under the auspices of the Australian and New Zealand Divisions of the Royal Aeronautical Society.

There are many legal issues involved in the provision and use of new technology based on satellite navigation and communications in Air Traffic Management Systems. These include aspects of international space law, international air law and domestic state law. Spanning these aspects are regional provisions and the role of ICAO. This paper considers these issues with particular reference to the Pacific region, which is in the lead in adopting the new technology, and concludes that much of the existing law applies, but that new law is also required if the legal framework is to keep pace with introduction of the new technology.

The potential benefit of predictive information for navigation support was investigated in a simulator study. Twelve participants had to guide a medium-size vessel across a traffic separation scheme. In the simulator, critical vessel traffic scenarios were created, where participants were provided with: (i) baseline Automatic Radar Plotting Aid (ARPA) information, and (ii) baseline ARPA information supplemented with capability prediction information. This is information that shows the predicted manoeuvring margins of the vessel, indicating the predicted boundaries of safe operation. Results of the experiment indicate that capability prediction allows better anticipation by the navigator, significantly improving ship navigation performance.

Bridge design has undergone changes in the last few decades resulting in increased awareness of the need for safety while maintaining the minimum of personnel. The concept of the one-person bridge has been studied fairly extensively with respect to military and large merchant vessels, but much of this work has been ignored by those designing for smaller ships, particularly fishing vessels. This paper derives principles for positioning the electronic fishing aids of ‘single ticket’ fishing vessels while applying, where applicable practically, the ergonomic principles developed from the wider community. The paper then applies the principles to the wheelhouses of two fishing vessels and suggests modifications for greater compliance. A conceptual wheelhouse design is given that satisfies all the principles while including the usual suite of electronic aids typically carried by such fishing vessels.

Controlling a ship in a berthing operation is carried out mainly by the change of state, such as velocity and yaw rate (turn rate), although the value of the change of state is very small at berthing. Very high precision is, therefore, required to determine the velocity and angular velocity. A sensor that has an accuracy of ±0.02°/s (1 σ) is sought for determination of turn rate in a berthing system. Three-dimensional angular velocity can directly be determined, with 2 independent baselines of 3 GPS antennas, using instantaneous Doppler measurements or phase rate (temporal difference of phase) observations. This paper discusses the mathematical model for direct determination of angular velocity using GPS, and the comparison of the results of the angular velocity determination using the Doppler and phase rate. The precision of angular velocity determination is estimated using temporal difference of the attitude sensors (TSS and gyrocompass) on board a hydrographic sounding ship. The RMS values of the difference of yaw rate determination between the two systems were: ±0.16°/s using phase rate and ±0.31°/s using Doppler measurements with the separation of onboard antennas of ca. 1·34 m. 10 m baselines could satisfy the sensor requirements for angular velocity determination during berthing maneuvers.