The ability of animals to find their way, without the benefit of mechanical or electronic aids to navigation, has fascinated humans for centuries. Relying on innate knowledge, coupled with the extraction of navigational data from the natural features of the universe, animals continually confound humans with their skills in locomotion. The magnetic compass, sun compass, strip maps, snapshots, target maps, temperature charts and star charts are known to feature in the overall animal navigation kit. Each species selects the most appropriate ‘map/chart’ and navigation kit for its environment.

If you ask the average Briton, he will tell you that Robert Watson-Watt invented radar in 1935. A German, asked the same question, would reply Christian Hulsmeyer in 1904. Strictly speaking, neither reply would be correct. It is generally accepted that the acronym RADAR stands for “Radio Direction and Ranging”, thus a practical radar system requires that both direction and range be determined. For this, the development of high power pulse transmission, and techniques for direction finding and timing of very short time intervals were needed. Over a period of years, these were individually developed for other purposes, but radar arrived only when all were combined into a single system. By 1939 radar development was also proceeding in a number of countries including France, Holland, Russia and the USA, but only the United Kingdom and Germany had brought it to an operational state.

The distinguished historian and author Correlli Barnett was invited to address members of the Royal Institute of Navigation at their Annual General Meeting held in the Royal Geographic Society on 23 October 2002. The full text of the address is reproduced. © 2003 Corelli Barnett.

The main problem in bringing autonomy to any vehicle lies in the design of a suitable guidance law. For truly autonomous operation, the vehicle needs to have a reliable Navigation, Guidance and Control (NGC) system of which the guidance system is the key element that generates suitable trajectories to be followed. In this review paper, various guidance laws found in the literature and their relevance to autonomous underwater vehicles (AUVs) are discussed. Since existing guidance laws for underwater vehicles have emulated from tactical airborne missile systems, a number of approaches for the missile guidance systems are considered. Finally, potential guidance strategies for AUVs are proposed.

During the course of its development for military use and more recent extension to many civilian uses, vulnerabilities of Global Navigation Satellite Systems (GNSS) – in the United States the Global Positioning System (GPS) – have become apparent. The vulnerabilities arise from natural, intentional, and unintentional sources. Increasing civilian and military reliance on GNSS brings with it a vital need to identify the critical vulnerabilities to civilian users, and to develop a plan to mitigate these vulnerabilities. This paper summarizes the findings of the U.S. Department of Transportation (DOT) vulnerability study that addresses these issues. The key findings are that satellite navigation users are vulnerable to several classes of disruption that affect all transportation modes and related infrastructure; but also that the vulnerabilities can be mitigated by awareness, planning, and using independent backup systems and/or alternate procedures in safety-critical applications. To gain the full benefits of GNSS, it will be necessary to analyse safety-of-life vulnerabilities in detail, and to determine the means and costs of reducing these risks to acceptable levels. The complete assessment report, of which this paper is a synopsis, was released to the public on September 10, 2001. Although the basic findings apply to all GNSS, the assessment focused on the GPS, in response to the enabling Presidential Decision Directive.

The maritime radiobeacon differential GNSS service in Europe has recently been reorganised with the aim of having at least two of the 162 stations serve each critical coastal location. Maritime administrations have now set specifications for the availability and continuity of the service. The paper analyses these requirements, noting incompatibilities between them. It proposes a method of predicting the performance of beacons, employing IALA standards. This takes into account each beacon's own availability, and propagation factors that include groundwave signal attenuation, interference, and skywave fading at night. Availability, continuity and coverage maps produced by the new programs are presented in the paper.

Collision avoidance is an intensive discussion issue for navigation safety. This article introduces a new routing algorithm for finding optimal routes with collision detection and avoidance on raster charts or planes. After the required data structure of the raster chart is initialized, the maze routing algorithm is applied to obtain the particular route of each ship. Those ships that have potential to collide will be detected by simulating the particular routes with ship domains. The collision avoidance scheme can be achieved by using the collision-area-marking method with collision avoidance rules at sea. The algorithm has linear time and space complexities, and is sufficiently fast to perform real-time routing on the raster charts.

The International Maritime Organization has mandated carriage requirements for VHF Automatic Identification System (AIS) on vessels over 300 tons by 2007 (IMO SOLAS: 1974 and IMO Resolution MSC.99(73)). The AIS will transmit a vessel's position and voyage data to other AIS-equipped vessels and shore-based authorities. It was envisioned that AIS data could enhance the safety of navigation by allowing vessels to quickly identify each other and use Digital Select Calling (DSC) to arrange maneuvers. We will discuss the history and the development of AIS, the technical issues surrounding its use by the mariner as a navigation tool and the pros and cons of the proposal by the US Coast Guard (USCG) to use AIS as a means of surveillance for Maritime Domain Awareness.

The Chairman of the Sea Safety Group has most kindly agreed to the publication of this definitive paper on the hazards to be encountered by mariners when transiting the Dover Strait. The paper brings together the deliberations of the SSG Navigation Panel and the best information available to them sent from all quarters of the sharp end of the marine industry to produce a paper which provides a centre for discussion on this difficult and controversial issue. The Sea Safety Group retains the copyright.

The volume of air traffic has increased considerably in the United Kingdom in recent decades and with further predicted increases, there is concern that safety is not compromised. In the UK, the number of occurrences is a key safety performance indicator. An occurrence can be thought of as a failure in the chain of operations in the air traffic system. Some of these occurrences result in a loss of separation between aircraft, varying from a slight loss of separation posing no danger of collision to a very serious loss with a significant risk of collision, known as an airprox. However, in the UK this definition is extended to include controller overload that does not necessarily involve a loss of separation. This paper analyses recent occurrence trends in the UK airspace attributed to air traffic control during the period 1998 to 2000 using data from the Civil Aviation Authority and the United Kingdom Airprox Board. The results indicate a decline in the rate of occurrences over the period 1990–1999 due to safety aids on board aircraft and in control rooms. Furthermore, the different conditions under which airproxes occur have been explored and observations made on duration and causes of controller overloads.

A theoretical analysis of the effects of dual frequency ionosphere propagation correction on GNSS code tracking noise is presented. The effect on tracking noise of using different combinations of the proposed Galileo signals for ionosphere propagation correction is investigated. It is concluded that, for the open or commercial service user, the Galileo signals E2-L1-E1 near to and around GPS L1 should be used to apply ionosphere propagation corrections to the E5 signals. This produces a tracking noise standard deviation about three times larger than that on an E5 signal alone. An ionosphere correction-smoothing algorithm is presented that reduces the tracking noise on the corrected pseudo-range measurements.

Onboard train positioning (navigation) plays a vital and safety critical role in advanced Automatic Train Control (ATC) and Automatic Train Protection (ATP) systems. Such onboard systems are also essential for moving block signalling and control systems for railways. The application of multi-sensor fusion algorithms to the vehicle navigation field has made it possible to create inexpensive and accurate positioning systems, which will satisfy the railways' requirements. The state estimation methods involved in Kalman filtering have proved to be some of the most effective techniques in multi-sensor data fusion. A multi-sensor navigation system is introduced in this paper to address the shortcomings of the existing train positioning systems. The proposed system utilizes the Global Positioning System (GPS), Doppler radar, gyroscopes, tachometers, digital maps and balises. In order to provide fault detection and isolation capabilities, a hierarchical structure is proposed for the multi-sensor integration system in which different combinations of navigation systems would function. Several data integration nodes, including DR/GPS, DR/Balise, and DR/GPS/Balise, are studied in more detail and their performances are evaluated.

This paper assesses the capability of GPS to provide the level of safety required for different aircraft flight navigation operations. It presents an analysis of the protection offered against potential catastrophic GPS failures at system and user levels. This is followed by an assessment of the different approaches to augmenting GPS for civil air navigation. Results show the inadequacy of GPS as a system for real-time safety critical use.

A model is developed for lateral collision risk in air traffic track systems, which resolves the problems of the Reich Model. It is a direct and concrete approach focusing on events, in contrast to Reich's synthetic methodology, in which (e.g.) three types of collision have to be modelled and the focus is on flying hours spent away from the planned flight path. This model makes it straightforward to see what is being assumed, and easy to understand the roles of the main parameters. It is a good starting point for the incorporation of collision detection and the use of hazard analysis.

In this paper a brief review of Sage adaptive filtering is followed by an analysis of the shortcomings of covariance matrices formed by windowing residual vectors, innovation vectors and correction vectors of the dynamic states. A new adaptive Kalman filter is developed by combining the Sage filter and the variance components and its use tested against various other schemes.

This paper offers a designed Integrated Navigation System that will permit vessels to transit safely through the Suez Canal avoiding collision and grounding in all weather environments instead of being directed to anchor, thus keeping the Canal open at all times for ship transits. The Suez Canal Integrated Navigation System (SCINS) includes Differential Global Positioning System (DGPS), Suez Canal LORAN-C system, and Vessel Traffic Management System (VTMS). The combination of DGPS and LORAN-C systems would provide real-time DGPS corrections that could be used to calibrate the Loran fix; this can be achieved by means of portable integrated DGPS/LORAN-C sets installed aboard the vessels. The addition of VTMS provides significant capability for preserving system accuracy during periods of GPS outages. Due to the interface between LORAN-C and VTMS systems, the SCINS will be able to solve the problem of targets that cannot be tracked by VTMS radars in the shadow areas behind the new bridges along the Canal. The SCINS automates position fixing in real-time, offers a designed algorithm to return the ship to the middle of the Canal and computes the cross-track error (XTE) and the ship squat. Kalman Filter design and system level performance predictions for the SCINS are briefly described. Simulation results show that the SCINS offers superior performance and better position accuracy than current integrated systems.

The September 2002 issue of The Journal included a paper that implied that the US practice of negotiating collision avoidance manoeuvres by VHF had effectively been endorsed by the IMO. That view is challenged, by reference to the relevant provisions in the US legislation, the COLREGS and chapter IV of the SOLAS Convention. This paper also concludes that AIS will be a useful tool to provide additional information, but should not alter the way in which the COLREGS are to be applied.

This paper is based on two articles by the authors that were published in the March and September 2002 issues of the Journal of Japan Institute of Navigation.

The collision risk to multiple targets and identification of feasible evasive manoeuvres can be assessed simultaneously in true motion by judging the tip of own ship's velocity vector in relation to the display of cone-shaped collision danger regions to acquired targets. Simulator test programmes composed of scenarios with various traffic densities and different speed ranges of own ship have been carried out in order to evaluate the performance of this collision avoidance display versus ARPA (true and relative motion) displays. Experienced navigators and maritime university students with license participated as test subjects. It is shown that the proposed display is capable to facilitate more homogeneous, precise and safe evasive manoeuvres than utilising conventional judgement techniques. The superiority increases with the excess speed of own ship, traffic density and complexity.

The main problems faced by a dynamic model within a Kalman filter occur when the system experiences unexpected dynamic conditions, a change in data acquisition rate, or when the dynamics of the system are non-linear. To minimize the errors produced from dynamic modelling in unusual conditions, an extended dynamic model is developed in this paper, and its usefulness demonstrated through comparison of the performance of a Kalman filter's response to simulated data with a standard dynamic model and the extended dynamic model. The results show that, in use, the proposed extended dynamic model is superior to a standard dynamic model, due mainly to its ability to adapt to a wider range of dynamic conditions, which in turn ensures the optimization of the Kalman filter and the consequent generation of reliable positioning results.

A localization system using GPS, ABS sensors and a driving wheel encoder is described and tested through real experiments. A new odometric technique using the four ABS sensors is presented. Due to the redundancy of measurements, the precision is better than the method using differential odometry on the rear wheels only. The sampling is performed when necessary and when a GPS measurement is performed. This implies a noticeable reduction of the GPS latency, simplifying the data-fusion process and improving the quality of its results.