The use of the required navigation performance (RNP) procedure has been increasing for aircraft navigation, since it allows for better optimisation of the airspace, which is increasingly congested. The present work aims to investigate the application of the functional resonance analysis method (FRAM), combined with the quantitative analysis provided by the Bayesian belief network (BBN), to demonstrate the existing variability in functions that are part of the complex navigation system based on the RNP procedure, specifically when the aircraft approaches the airport (approach phase). As a result, it is possible to analyse the variability that occurs in the studied system and the BBN complemented the study by allowing a quantitative interpretation of the functions considered most important for the execution of an RNP approach procedure.

We present a deep learning approach for near real-time detection of Global Navigation Satellite System (GNSS) radio frequency interference (RFI) based on a large amount of aircraft data collected onboard from the Global Positioning System (GPS) and Attitude and Heading Reference System (AHRS). Our approach enables detection of GNSS RFI in the absence of total GPS failure, i.e. while the receiver is still able to estimate a position, which means RFI sources with low power or at larger distance can be detected. We demonstrate how deep one-class classification can be used to detect GNSS RFI. Furthermore, thanks to a unique dataset from the Swiss Air Force and Swiss Air-Rescue (Rega), preprocessed by Swiss Air Navigation Services Ltd. (Skyguide), we demonstrate application of deep learning for GNSS RFI detection on real-world large scale aircraft data containing flight recordings impacted by real jamming. The approach we present is highly general and can be used as a foundation for solving various automated decision-making problems based on different types of Communications, Navigation and Surveillance (CNS) and Air Traffic Management (ATM) streaming data. The experimental results indicate that our system successfully detects GNSS RFI with 83$\,\cdot\,$5% accuracy. Extensive empirical studies demonstrate that the proposed method outperforms strong machine learning and rule-based baselines.

The rapid development of differential GNSS transmissions via low-frequency maritime radiobeacons has further increased the occupancy of an already over-crowded frequency band. This has resulted in interference between stations, with consequent reductions of coverage. The paper suggests a re-allocation of channels within this band in Europe to be carried out, taking careful account of the known groundwave and skywave propagation of both wanted and interfering signals and the distribution of atmospheric noise. A novel algorithm is proposed for re-allocating frequencies. The resulting band plan is shown to offer substantially increased coverage for DGNSS radiobeacons while preserving the performance of marine and aeronautical direction-finding beacons, the latter remaining on their original channels.

Recent advances in technology have encouraged proposals for new approaches to ATC in Europe and elsewhere. Two such proposals, both rather loosely framed, are for ‘free flight’ or for ‘seamless contracts’; otherwise ‘tubes of flight’. These concepts, and variations on them, aim to increase the traffic capacity of the airspace. They have been the subject of numerous published papers. Given the declared objects of these systems, it is surprising that, nearly without exception, these papers discuss the proposals only in qualitative terms. The present paper discusses idealised versions of these systems on the basis of quantitative studies. It is concluded that the ‘seamless contract’ is very probably unworkable in Europe. ‘free flight’ is workable in principle, but there is a need for investigation of possible mechanisms by which last-minute problems may be resolved.

Civil Marine Radar (CMR) is now a mature instrument of some 50 years steady development. Following a short history, more to provide benchmarks of achievement than to satisfy historians, this paper examines what will drive the future development of CMR. The answer may not follow recent developments, but may well be the result of a fresh maritime modus operandi to fulfil the navigation, collision avoidance and safe passage needs of all types of craft operating in all types of water with different pressures and Operational Requirements (ORS). Having postulated fresh ORS, suggestions are made on how best to fulfil them in a logical and cost-effective manner.

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.

As essential specifications of correlation domain for signal quality evaluation, distortions of the S-curve, including bias and slope distortions of the zero-crossing point, are usually selected as indicators of optimisation in the process of designing the channels of receivers or navigation satellites. Focusing on this issue, we present a detailed analysis of slope distortion in the presence of group delay and amplitude distortions. After validating the theoretical results, we present further discussions about the impacts of different group delay terms on slope distortions. The results indicate that both the odd-order and the even-order terms have impacts on the slope distortion, and higher odd-order terms have less slope distortion compared with the lower odd-order terms. These results are useful for evaluating the slope distortion from the group delay and guiding improvement in design of the channel.

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.

To solve the problem of spacecraft attitude manoeuvre planning under dynamic multiple mandatory pointing constraints and prohibited pointing constraints, a systematic attitude manoeuvre planning approach is proposed that is based on improved policy gradient reinforcement learning. This paper presents a succinct model of dynamic multiple constraints that is similar to a real situation faced by an in-orbit spacecraft. By introducing return baseline and adaptive policy exploration methods, the proposed method overcomes issues such as large variances and slow convergence rates. Concurrently, the required computation time of the proposed method is markedly reduced. Using the proposed method, the near optimal path of the attitude manoeuvre can be determined, making the method suitable for the control of micro spacecraft. Simulation results demonstrate that the planning results fully satisfy all constraints, including six prohibited pointing constraints and two mandatory pointing constraints. The spacecraft also maintains high orientation accuracy to the Earth and Sun during all attitude manoeuvres.

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).

This paper describes a precision position and time service which could support the increased air traffic of the future, with an example of its application to air traffic control. Horizontal position and epoch time distribution are provided by Loran-C and vertical position by digital barometric altimetry. The proposed use of these systems for horizontal navigation, vertical positioning and landing approach is based on their successful use by current high-speed aircraft. The paper was presented at the 19th Technical Conference of I.A.T.A., Dublin, October 1972.

Recent work on marine traffic engineering in Japan was reviewed in four papers published in this Journal in 1971. In the present paper, which may be regarded as a sequel to these, Professor Makishima offers some theoretical comments.

This paper is a report on some early findings of a long-term study which has the ambitious objective of suggesting better alternative solutions to the general problem of controlling a collection of aircraft. The study aims to answer questions about the optimum division of responsibility between the aircrew and ground A.T.C., about the way in which the A.T.C. tasks are shared between a number of controllers and A.T.C. computers, and about the fundamental principles on which traffic flow is organized.

Mr. Bell and Professor Stratton have in the October Journal shed interesting light on the nature of inertial navigation as applied to navigation around a planet. It is a pity that Mr. Bell has repeated that in such inertial systems vehicle position and velocity are deduced from measurement of acceleration. This idea is certainly misleading so far as understanding error propagation in these systems is concerned, if not actually wrong.

Although the Astrograph has never been formally described in print, the basic principles of the instrument are sufficiently well known to require no further elaboration; so also are its limitations. Over many years, numerous proposals (but mainly unpublished) have been made for the extension of the Astrograph to cater for the Sun, Moon, and planets, as well as for a larger number of stars, but none have been really satisfactory. Without such improvements the Astrograph must have a very limited use, and accordingly a further study was made some time ago of its application to the Sun, Moon, and planets. Methods were developed on familiar lines for shifting (and rotating) the star curves for a standard declination to cater for neighbouring declinations, but these introduced complexities that were clearly unacceptable.

This paper outlines some of the results being achieved by the UK research programme on civil avionics which is based at RAE Bedford. Acknowledgments are therefore due to members of the civil avionics team and UK industry from whose work these examples are drawn, and not least to the Department of Trade and Industry who fund the programme.

No attempt is made to define ‘flight management systems’. The concept, originating in the complex outer loops of autopilots, has now come to include all the detail involved in managing the flight deck systems as well as planning and controlling the aircraft's progress from ramp to ramp. As this paper will hope to demonstrate, the concept is still growing.

Time and space scales are compared for selected speeds of ships in the North Atlantic and North Pacific oceans. Viability of westbound passages on some northern great circle routes is discussed.

There would be no problem in precisely weather routing a vessel across an ocean if it were possible to forecast with total accuracy the actual sea state existing for the duration of a voyage. All mariners are well aware that such an ideal circumstance is not as yet possible. Depending upon the general synoptic situation existing for the period, it is fair to make the assumption that the actual accuracy of a weather forecast deteriorates as time progresses.

The objects of the International Geophysical Year have been fully described in the Journal. The idea itself was first conceived in 1950 at a social gathering in the home of Professor J. A. van Allen, in Maryland, U.S.A. The small group included Professor Sydney Chapman of Great Britain and Dr. Lloyd Berkner of U.S.A., now respectively the President and Vice-President of the special committee for the International Geophysical Year. They considered that recent advances in geophysical science were such that an interval of fifty years, such as lay between the First and Second Polar years, would be too long. Moreover an interval of twenty-five years from the Second Polar Year would coincide with a period of maximum sunspot activity. Later in the same year the International Council of Scientific Unions adopted the idea and in the following year set up the special committee; at the same time the nations adhering to I.C.S.U. were invited to form national committees, of which there are now more than sixty. Their programmes make up the vast international world-wide effort. A duration of eighteen months, July 1957 to December 1958, for the Year was agreed.

Rule 10 of the new Collision Regulations deals with the conduct of vessels in Imco adopted traffic separation schemes. In this paper, which was presented at a meeting of the Institute in London on 20 April 1977 with Commander R. B. Richardson, R.N. (ret.) in the Chair, Commander Paton, Hydrographic Adviser to the Department of Trade, discusses the traffic situation in the English Channel and Southern North Sea in the light of this Rule with particular emphasis on encounter situations at route junctions and the problems of crossing traffic.