bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ground-Based 4-D Guidance of Flights in Strong Winds
Authors: Benoît André , Swierstra Sip 
Published: October 2009

In a strong wind, groundspeed may vary appreciably during a turn, as, for example, in the case of a landing after a U-turn preceding the localizer intercept. Such conditions are critical for maximum use of the runway, and render human estimation of aircraft motion extremely difficult.This paper summarizes the tests conducted using a ground-based 4D-guidance program, developed to assist the air traffic controller in maintaining the predicted landing-time sequence with an accuracy better than 10 seconds for each arrival.
The Control of Inbound Flights
Authors: Benoît André , Swierstra Sip 
Published: October 2009

This paper describes the basic principles of a method developed to guide aircraft accurately down to the runway in a time-of-arrival constrained environment. The method is designed to be used in a ‘zone of convergence’ context or in any similar advanced air traffic control system characterized by the integration of control phases over an extended area on the one hand and true ‘computer assistance’ to the air traffic controller on the other; that is, assistance provided at the decision-making level through the automatic generation of guidance advisories.The method includes two closely-coupled basic components; namely, a ‘predictor’, which computes a trajectory once initial conditions and plans are known, and a ‘profile manager’, which adapts the plans to meet the time constraints and generates the guidance directives on the basis of present position, actual surveillance information, aircraft operation and route constraints.
Civil Marine Radar Developments in the Eighties
Authors: Ibbetson E. R. 
Published: October 2009

This paper was presented at an RIN meeting on ‘Air and Marine Radar Developments’ on Wednesday 16 January 1991.During the last decade there have been significant developments in the civil marine radar field, resulting in: (1) Improved radar detection performance; (2) Improved operational facilities; (3) Improved reliability; (4) High brightness, daylight viewing, colour and monochrome displays with full ARPA performance; (5) Integrated radar and navigation systems; (6) Reduction in costs.
Geostationary Augmentation of Global Satellite Navigation–1991 Update
Authors: Kinal George V. , Nagle Jim 
Published: October 2009

This paper and the following five papers were presented at the NAV91 Conference on Satellite Navigation held at Church House, London, 6–8 November 1991. Copies of the conference proceedings are available from the Director, price £85 (non-members) and £65 (members).In the last two years, the idea of a civil geostationary overlay (augmentation) to GPS and GLONASS has moved from the discussion/concept stage to something approaching reality. Many details of implementation have been or are in the process of being determined. Major developments that have taken place in this period of time include: (i) INMARSAT'S adoption of a four ocean region satellite deployment (three had been employed previously), now including one region (AOR-West) that covers the conterminous United States, (ii) Inclusion in the specifications, and contracting for, navigation repeater payloads in the four INMARSAT-3 spacecraft, now under construction, (iii) Major improvements in the Test Bed, bringing the test signals closer in function and structure to those to be provided through the INMARSAT-3 navigation payloads. (iv) Plans in the US and Europe to employ the Test Bed, or a facsimile thereof, for field trials of the GPS/GLONASS integrity channel (GIC) concept, (v) Endorsement of the ‘Wideband GIC’ concept (transmission at GPS L, frequency of a spread spectrum signal) by many members of the aviation community, (vi) Introduction and study of the possibility that the Gic might be able to carry some form of differential corrections in addition to the basic integrity and constellation augmentation functions. In other words, whereas two years ago we were still considering the possibility of a civil element of global satellite radionavigation, this year we are deeply in the process of putting the necessary elements into place.
TMSIM: A Runway Capacity Study for Frankfurt and Chicago O'Hare Airports
Authors: Trivizas Dionyssios 
Published: October 2009

A realistic runway capacity study for two major airports, namely Frankfurt (EDDF) and Chicago O'Hare (ORD) is presented, assessing the effect of optimal scheduling on the runway capacity and air traffic delays. The maximum position shift (MPS) runway scheduling algorithm, used in the study, was developed by Trivizas at the Massachusetts Institute of Technology (1987).EDDF is studied in the context of 160 major European airports, with a real traffic sample from 6 July, 1990. ORD is studied in the context of 26 major US airports using a large traffic sample from 1 March, 1989. Secondary airport traffic has been assigned to the geographically nearest major hub and time compression has been used to extrapolate to an artificially denser scenario.The results show that optimal scheduling can bring about capacity improvements of the order of 20 percent, which in turn reduce delays up to 70 percent. These results are the product of a dynamic traffic management process which has been visually validated by observing animated runway operations and monitor functions.The study has been conducted with TMSIM, a comprehensive, object-oriented simulation tool that allows one to build an understanding of the structure and functionality of the air traffic control system, by modelling its components, their functionality and interactions, and measuring component and system performance. It features interactive route network editing (using menu/mouse techniques), complete route and airport structure modelling, independent flight and ATC objects, 3-D animation, advanced algorithms for scheduling, routeing, flow management, airspace restructuring (sectorization) and performance (capacity and communications workload) analysis.
Data Representation Using a Standard Data Transfer Specification
Authors: Killick James 
Published: October 2009

In the 1990s, digital maps are being used for a wide variety of applications. In the world of digital road maps, the most notable applications are in the area of theIntelligent Vehicle Highway Systems (IVHS). In the USA IVHS is involved with five basic interrelated applications:(i) Advanced Traffic Management Systems.(ii) Advanced Vehicle Control Systems.(iii) Commercial Vehicle Operations.(iv) Advanced Public Transportation Systems.(v) Advanced Traveller Information Systems.
Navigation Philosophy Past and Future
Authors: Burnett Adrian 
Published: October 2009

In his Presidential Address at the 45th Annual General Meeting in October 1991, Norman Dahl gave a thought-provoking discussion of the future of the navigator. He suggested that the navigator's trade is not just a changing trade, but a vanishing one. He proposed then, and subsequently in his 1993 Anderson Memorial Lecture (reproduced as the previous paper in this issue of the Journal), that consideration should be given to the future of navigation, the future of the navigator and the future of the Institute.In this contribution, papers and addresses over the history of the Institute are examined critically to extract insights into navigation applicable to the present era. These are used to discuss and develop the meanings of the terms ‘navigator’ and ‘navigation’.
Comments on Ship Domains
Authors: Jingsong Zhao , Zhaolin Wu , Fengchen Wang 
Published: October 2009

The ship domain is a very important and useful concept in marine traffic engineering. It has been widely used in traffic simulation models, for encounter criteria, traffic lane design criteria, VTS planning, risk assessment, collision avoidance, and for other applications.Dr Y. Fujii, Dr E. M. Goodwin and Dr T. G. Coldwell have done a lot of work on this subject. The differences between their ship domain concepts are described in the second part of this paper. In the third part, the authors have used a new branch of social psychology – the theory of Proxemics – to analyse the factors which affect the ship domain, and point out that the basis of producing ship domains is in the field of Proxemics. Finally, in the fourth part of this paper, some problems in ship domains are analysed.
Comparison of Two Multi-site Reference Station Differential GPS Systems
Authors: Johnston G. T. 
Published: October 2009

This paper describes the infrastructure and concept of two multi-site reference station differential GPS (DGPS) options being offered to land and marine users by Racal Survey. The infrastructure of the Racal SkyFix system is briefly outlined followed by descriptions of Racal's internetting and network capabilities.The two systems are compared including infrastructure, differential data management, user coverage, datalinks and positioning performance in various parts of the world. The paper describes the design of each of the systems and the tests undertaken to assess their functionality, before going on to compare their performances under a variety of conditions. Emphasis is placed on the technical issues associated with multi-reference station DGPS including error sources, weighting observations and monitoring of the data. The fundamental approach of the systems is shown to achieve high data integrity which is necessary to develop the systems to their next phase.Having described the two options, examples of various combinations of reference stations are used to illustrate the potential of the system and to show the increased performance over ordinary, single-station DGPS. The conclusions summarize the paper's findings and make recommendations for the future development of the system. The object of the developments so far have been to improve the quality of real-time offshore DGPS positioning. The internetting and network options are providing real-time results to illustrate the benefits and, together with SkyFix, offer significant developments in the ability of DGPS to provide accurate and reliable positioning over vast areas of the world.
The Management of Marine Traffic, A Survey of Current and Possible Future Measures
Authors: Degré Thomas 
Published: October 2009

The risks involved in maritime transport are very much greater now than was formerly the case. This has been accompanied by a considerable increase in the damage resulting from certain accidents. Maritime traffic management has been made necessary not only for reasons of safety but also productivity and comprises two main types of measure: first, laying down and enforcing suitable regulations and secondly, providing navigators with real time information which is not available to them on board from the Vessel Traffic Services (VTS).Section 2 of this paper is a general description of the techniques used in maritime traffic management and an account of possibilities for the future. Section 3 describes a feasibility study for a traffic monitoring aid system based on VTS and using a knowledge based system.This paper is based on one which was first published in the journal, Recherche Transports Sécurité, issue no. 9, 1993.
Strategic Planning of Vessel Traffic Services using ABS Analysis and Optimization
Authors: Babu A. J. G. , Ketkar W. 
Published: October 2009

Vessel Traffic Services (VTS) advise vessels navigating the waterways, VTS communications provide to the mariner timely, pertinent, and accurate information that would assist in safe manoeuvring of the vessel.Following several oil spills in 1989, Congress passed The Oil Pollution Act of 1990 (Public Law 101–380). The Act requires the “Secretary to conduct a study…to determine and prioritize the US ports and channels that are in need of new, expanded, or improved vessel traffic service systems.…”As required by the Act, the US Coast Guard analysed historical vessel casualties and their consequences and projected future vessel casualties and consequences for 23 study zones. The study uses a benefit–cost approach, VTS benefits are defined as the avoided vessel casualties and the associated consequences. The avoided consequences are measured in physical units and are assigned monetary values, VTS costs are defined as the initial federal investment for a state-of-the-art VTS system in each study zone and its annual operating and maintenance costs. Both the benefits and costs are expressed in the 1993 Net Present Value of annual stream over the life cycle at 10 percent basic annual rate. The study recommends VTS design by rank-ordering the zones by net benefit.In this paper, we use alternative methodologies for offering better assistance in making VTS design decision-making. First, we perform ABC analysis on the zones; that is, we classify them into three groups: The A group deserves a state-of-the-art, full-fledged VTS presence, the B group could use an intermediate level of VTS services, and the c group deserves an elementary level of VTS services, as and if the budget permits. This analysis assumes that VTS services can be offered at various levels with correspondingly changing costs. Secondly, we perform resource allocation analysis; that is, for a given budget and given criterion (e.g. maximize the total benefit), select the optimal zones in which the VTS services should be offered. This analysis, done for various levels of budget, would form a useful decision aid for the VTS design.
Detection of Marine Radar Targets
Authors: Briggs John N. 
Published: October 2009

A radar must detect targets before it can display them. Yet manufacturers' data sheets rarely tell us what the products will detect at what range. Many of the bigger radars are Type Approved so we consult the relevant IMO performance standard A 477 (XII). Paraphrasing Section 3.1 of the draft forthcoming revision (NAV 41/6): under normal propagation conditions with the scanner at height of 15 m, in the absence of clutter, the radar is required to give clear indication of an object such as a navigational buoy having a radar cross section area (RCS) of 10 m2 at 2 n.m. and, as examples, coastlines whose ground rises to 60/6 m at ranges of 20/7 n.m., a ship of 5000 tons at any aspect at 7 n.m. and a small vessel 10 m long at 3 n.m.This helps, but suppose we must pick up a 5 m2 buoy at g km? What happens in clutter? Should we prefer S- or X-band? To answer such questions we use equations which define the performance of surveillance radars, but the textbooks and specialist papers containing them often generalize with aeronautical and defence topics, making life difficult for the nonspecialist.This paper attempts a concise and self-contained engineering account of all main factors affecting detection of passive and active targets on civil marine and vessel traffic service (VTS) radars. We develop a set of equations for X- and S-band (3 and 10 cm, centred on 9400 and 3000 MHz respectively), suited for spreadsheet calculation.Sufficient theory is sketched in to indicate where results should be valid. Some simplifications of conventional treatments have been identified.
ACAS in Europe – a U.K. View
Authors: Thorning A. G. 
Published: October 2009

The views expressed in this paper are those of the author and do not necessarily represent CAA policy.The author would like to give grateful acknowledgement to the various companies from which information has been received. (Note that the original presentation at a RIN ordinary meeting was illustrated by numerous colour slides which cannot be reproduced here, as well as three video films).
The Navigator's Yeoman
Authors: Agnew H. J. , Woolley R. K. , Parfitt G. 
Published: October 2009

This paper is concerned with potential improvements in the way man interacts with machines, maps and charts. Particular motivation comes from the new navigational challenges provided by the increasingly widespread use of electronic position-fixing aids in the marine field. Whilst automatic plotting tables and moving light spots have provided part of the solution in larger ships, much recent investment has been witnessed in the development of ‘electronic chart’-based systems.For a number of practical reasons, among which are the lack of available data bases for these systems and little updating and distribution infrastructure for them, it is believed that there is unlikely to be a wide acceptance of such equipment as the primary or sole plotting aid for a considerable number of years to come.Yeoman, a navigation plotting system which uses existing conventional charts, was conceived and developed to provide a simple and effective man–chart interface with few drawbacks. This paper provides the background for the development, the product and potential future evolution.
Evaluating the Feasibility of a Radar Separation Minimum for a Long-Range SSR
Authors: Nagaoka Sakae , Amai Osamu , Watanabe Yasuo 
Published: October 2009

This paper deals with an analytical method for establishing a separation minimum for air traffic control using a monopulse SSR (Secondary Surveillance Radar), namely the Long Range SSR (LSSR), of which coverage is extended to 250 n.m. The azimuth estimation accuracy of the monopulse SSR was significantly improved compared with that of conventional SSR.As an index of a collision risk due to azimuth errors of the LSSR, the close approach probability (CAP) associated with the probability of overlap of aircraft in azimuth is used for evaluating the safety of the surveillance system. The CAPs for both the LSSR and the conventional SSR are estimated by modelling and comparing distributions of azimuth errors. The CAP for the LSSR is significantly smaller than that for the conventional one under 5 n.m. separation minimum.
An Evil So Pregnant with Mischief: Some Influential Ups and Downs in the Development of Navigation Equipment and Practice
Authors: Fanning A. E. 
Published: October 2009

This paper formed the 1988 Anderson Memorial Lecture, and was presented to the Boscombe Down Branch on 17 March.Wing Commander Anderson, in addition to his many distinctions connected with our Institute (a Founder Member, President, Gold Medallist, Honorary Member and frequent office holder) was above all an indefatigable worker for the science and artistry of navigation, which he regarded as a basic activity of all mankind. In 1939 he was headmaster of a school and by 1945 had become one of the most outstanding operational navigators in the Royal Air Force. In that year he was chosen as navigator of the research aircraft, Aries I, for those epic flights over the North geographic and magnetic poles, investigating compass performance in high latitudes.
The ‘Automatic Gun Laying System’ – A Quantum Enhancement for the Royal Artillery
Authors: Symonds G. B. 
Published: October 2009

abstractThis paper was presented at an Ordinary Meeting of the Institute, held at the Royal Entomological Society, London, on Wednesday 20 April 1988.The current method of artillery survey is reviewed and its limitations examined in the light of both the system error budget and the envisaged battlefield threat. The concept of the Automatic Gun Laying System (AGLS) is introduced as a means of enhancing the effectiveness and survivability of the self-propelled gun element through the application of modern inertial navigation (IN) technology. As a complement to this, the use of IN technology to provide a vehicle-mounted target observation capability is also presented. The paper describes a unified treatment of the artillery system, leading to the selection of the respective IN solutions, and concludes that a standard module is both appropriate and optimal. Environmental factors are discussed, together with the alternative sensors and systems considered. The paper concludes with brief comments on the status of inertial navigation within the military land area.
Aircraft Automatic Landing Systems Using GPS
Authors: Parkinson B. W. , Fitzgibbon K. T. 
Published: October 2009

abstractThis paper is based on a presentation made at the IAIN International Navigation Congress held in Sydney, Australia, in February 1988.The global positioning system (GPS) offers a new opportunity for the automation of aircraft landing systems. The position and velocity measurements provided by a state-of-the-art GPS receiver using the C/A code and working in a normal or differential mode (D-GPS) and aided by one or two ground-based PseudoLites (PLS), may be able to satisfy the landing accuracy requirements of the FA A.This paper describes the design and simulation of an aircraft automatic landing system. Aircraft position and velocity are assumed to be measured using a (carrier-tracking) GPS receiver. The hypothesized capability is based on measurements taken at Stanford and elsewhere, using the Trimble 4000SX, five-channel receiver in an integrated-doppler-aiding mode. For some of the autopilot designs, either ground-based GPS transmitters (pseudolites) or a radar altimeter have also been incorporated.Included in the landing simulations are wind shears and a gust model, creating realistic landing situations. The performances of the lateral and vertical displacements are presented with their 1σ r.m.s. estimation errors during the glide-slope and flare phases. Included are different wind conditions, GPS configurations and controllers. The results are compared with the FAA requirements for various categories of automatic landing systems.
Spatial correlation as an early warning signal for transitions in ecosystems
Authors: Dakos Vasilis , van Nes Egbert , Scheffer Marten 
Published: October 2009

AbstractAn increasing number of sudden transformations triggered by small forces has been identified in a variety of ecological systems. Such changes are usually termed regime shifts between alternative states and their unexpected nature makes them challenging to handle from a management perspective. In the face of our limited mechanistic insight on the dynamics of such transitions, developing generic early warning signals for ecosystem regime shifts becomes a formidable task. So far, most of the research has focused on developing potential early warnings in simple models which ignore spatial interactions. In this work we spatially extended three well studied models that belong to the class of systems which undergo regime shifts through a fold bifurcation. All models were run on a two dimensional lattice with different spatial distributions of an environmental factor (e.g., soil fertility, water level). Where each patch in the lattice is individually governed by the same dynamics which eventually lead to alternative stable states, the response of the global spatial system is modified due to connectivity between patches. Our aim was to investigate whether we could identify a leading indicator of the imminent shift in the global spatial system.We followed the evolution of both spatial correlation between patches and temporal correlation within patches, obtained from stationary distributions, as we gradually increased a control parameter which causes the system to switch to its alternative attractor. We evaluated whether spatial correlation between neighboring patches can be used as a leading indicator of a system approaching a transition. Our analyses showed that spatial correlation between neighboring patches increases before the transition of the global spatial system into its alternative stable state. We demonstrated that spatial correlation between neighbors performs better as an indicator to an impending regime shift in heterogeneous conditions when compared to temporal correlation indicators. Despite differences between the three models, spatial correlation between neighbors appears to be a parsimonious and reliable early warning signal for transitions in spatial systems.