bluuebunny/crossref_metadata_2025 huggingface dataset:
Weather Satellite Information for Offshore Industry
Authors: Morris R. M.
Published: November 2009

The Meteorological Office makes full operational use of pictorial weather satellite data in preparation of routine analyses of the atmospheric fields of wind, temperature, pressure and humidity. There are two types of satellite, polar orbiting and geostationary: the polar orbiter scans the globe from a height of about 830 km and as the globe rotates beneath the satellite each area is scanned twice in 24 hours; the geostationary satellite rotates with the globe and takes frequent pictures of the same area from a height of about 35000 km.

The pictorial data are in the form of visual and infra-red images and when used together can provide considerable information about the height, type and density of the clouds. Vertical temperature profiles within the atmosphere are also retrieved from polar orbiting satellites using linear regression techniques, but there are problems yet to be solved in areas of heavy cloud and precipitation. The paper was presented at Oceanology International 1982, held at Brighton.
Present Development Phases of the Suez Canal Project
Authors: Hilaly Nabil
Published: November 2009

It is recorded that Egypt was the first country to dig a canal to promote world trade; the first canal was dug in the reign of Pharaoh Senusret III (1887–1849 B.C.), to link the Mediterranean Sea with the Red Sea through the Nile delta. This canal, often abandoned due to silting, was reopened for navigation by later Pharaohs and finally by Amro Ibn El Ass in A.D. 640 after which it remained open for 150 years.
II – The Reliability of Height and Identity Data
Authors: Gent H.
Published: November 2009

Secondary surveillance radar is a combined radar and communication system, which provides aircraft position (range and azimuth) on the radar side and identity and height on the communication side. It is a main working tool in Air Traffic Control today and the information it produces is an ingredient in providing separation between aircraft in flight. This paper is concerned only with the reliability of the identity (Mode C) and the height (Mode A) data, and not with the radar position data as such. ‘Reliability’ is taken to mean ‘can the values reported by the SSR be relied upon?’ Consequently we are not concerned with cases where an interrogation elicits no response, but only with responses which are present but not correct. Furthermore, a ‘Mode C discrepancy’ is defined as a read-out that disagrees with the altimeter reading observed by the pilot, so that we are not concerned with altimeter errors, but only with the faithfulness (or otherwise) with which the SSR reproduces the altimeter reading. In cases where the Mode C read-out is obviously wrong, but no pilot's report is available, it is not always possible to distinguish between an altimeter error and a Mode C discrepancy.
Direct Methods of Sight Reduction: An Historical Review
Authors: Cotter Charles H.
Published: November 2009

In general terms the principal problem in astronomical navigation is the solving of a spherical triangle - the PZX-triangle. The fundamental formula of spherical trigonometry for finding an angle given the three sides of a spherical triangle is the cosine formula. By transposition this formula can be used for finding a side given the opposite angle and the other two sides. Because the cosine formula is not suitable for use with logarithms numerous formulae have been derived from it with the aim of simplifying logarithmic computation. The term ‘direct method’ applies to a method the basis of which is generally the cosine formula or any of its derivatives although some direct methods are based on Napier's Rules for right-angled spherical triangles.
Distributed Processing in Modern Navigation Systems
Authors: Pearson M. G.
Published: November 2009

When computers were first used for navigation — mostly air navigation — there were debates as to whether all the computing should be done centrally or implemented by a series of smaller computers, each doing certain limited tasks. The debate was largely academic, since the technology for distributed processing did not really exist. Consequently, the development of navigation systems was centred on single processors and special-purpose input and out-put devices.
What do we do with Navigational Data?
Authors: Parker J. B.
Published: November 2009

A technical session on the above subject was held in London on 13 April 1983. The topic was introduced by Mr M. St Erme Cardew, who first stressed the distinction between navigational data and positional data. The former, unlike the latter, are referenced by time so that there is a sense of urgency in processing navigational data. Inherently these are always out of date, possibly only slightly, due to the finite processing time required. Some extrapolation is always required. He recognized the importance of errors, possibly gross ones, and distinguished these as due either to the assumptions made by the navigator being incorrect or to errors in the data. He advised checking the calculational methods, possibly by undertaking, via a computer, two or more independent analyses. Checking that incoming data were both stable and within specification was imperative. In an emergency it was necessary that human intervention into computer-produced information be accepted.
Estimating the Pressure Altitude of Aircraft by Radar
Authors: Nagaoka Sakae
Published: November 2009

A mathematical collision risk model can be used for evaluating air traffic control (ATC) separation standards. As one of the parameters required for calculating the expected number of collisions by this model, the probability of overlap in the vertical dimension based on height-keeping errors of aircraft must be estimated.

However, there are few examples of empirical data on height-keeping errors because data collection is expensive and time-consuming. In order to collect these data, the author et al. started data collection using a newly developed simple height-finding radar, the navigation accuracy measurement system (NAMS) which has been installed under a trunk airway in Japan.
The Development of Flight Deck Displays
Authors: Stringer F. S.
Published: November 2009

In this review of the evolution of displays and controls in military and civil fixed-wing aircraft, the author traces the development of flight instruments, largely in this country, from their rudimentary beginning before the first World War to the present high degree of automation and suggests certain pitfalls from the pilot's point of view in high-technology solutions.

The Wright Brothers' aeroplane flew with only a stopwatch, a tachometer to measure engine speed, and an anemometer, all for measuring performance; the pilot had no instrumentation to help him fly the aircraft. There was little change up to the beginning of the first world war in 1914. The cockpit hardly existed as such: controls varied in design; some were levers, and often there was a wheel which, in the early days, controlled wing warping to change the lift of each wing to allow the aircraft to bank.
A Graphical Assessment of the Close Quarters Situation
Authors: George B. D.
Published: November 2009

An article entitled ‘Defining the Close-Quarters Situation at Sea’ in this Journal (36, 454, September 1983), described how certain manoeuvres made by ships could safeguard against close-quarters situations developing at sea and, when circumstances demanded, these manoeuvres could ensure compliance with Rule 19(e) of the Collision Regulations.

Basically it was suggested that engines should be stopped when the distance between two such approaching vessels was N nautical miles, which was pre-calculated. If that action appeared insufficient, full astern power should be applied after an interval of Δt minutes had elapsed or, at the latest, when the separation distance between the two vessels was not less than Ab(SP) nautical miles.
Collision Avoidance, Driver Support and Safety Intervention Systems
Authors: Gilling Simon P.
Published: November 2009

Autonomous Intelligent Cruise Control (AICC) will be marketed by a number of vehicle manufacturers before the end of the decade. This paper will describe AICC and the next generation systems currently being developed and validated within the EC Fourth Framework project, Anti-Collision Autonomous Support and Safety Intervention SysTem (AC ASSIST).

The currently available cruise control systems which maintain a fixed speed are a well-known form of longitudinal driver support. The fixed speed cruise control becomes less useful with increased traffic volumes, as the driver must disable the system when a slower preceding vehicle is encountered.
A Tanker Navigation Safety System
Authors: Judson Brad
Published: November 2009

This paper summarizes the results of Phase 3 of the Arctic Tanker Risk Analysis Project (ATRA) which provided a prototype Tanker Navigation Safety System (TNSS). TNSS is a ship-board risk management system capable of route planning and decision support based upon a knowledge database. The objective of the project was to provide timely risk assessment information to a mariner or decision-maker in a system capable of integration with existing ECDIS or shipboard PC systems. The historical information was to include: accident location, frequency and type, ice, wind, visibility, environmental sensitivity and other factors. The specifications of the TNSS prototype were expanded so that risk could be assessed for each track in a route plan by applying a predictive accident model patterned after the navigation and collision avoidance process.
Collision Avoidance for Oarsmen on the Tideway
Authors: Prince R. G.
Published: November 2009

There are two places where landsmen and seamen are likely to come into conflict: (i) in the pubs around Portsmouth Docks; and (ii) in tidal estuaries such as the Thames. There is, however, an intermediate class of person, represented nowadays almost entirely by more or less amateur oarsmen and women, which is that of watermen. I am proud to consider myself a member of all three.
Vertical Sextants give Good Sights
Authors: Dixon Mark
Published: November 2009

Many texts stress the need for marine sextants to be held precisely vertical at the instant that the altitude of a heavenly body is measured. Several authors lay particular emphasis on the technique of ‘rocking’ the instrument in a small arc about the horizontal axis to obtain a good sight. Nobody, to the author's knowledge, however, has attempted to quantify the errors involved, so as to compare them with other errors inherent in determining celestial position lines. This paper sets out to address these issues and to pose the question: what level of accuracy of vertical alignment can reasonably be expected during marine sextant work at sea ?

When a heavenly body is brought to tangency with the visible horizon it is particularly important to ensure that the sextant is held in a truly vertical position. To this end the instrument is rocked gently about the horizontal so that the image of the body describes a small arc in the observer's field of vision. As Bruce Bauer points out, tangency with the horizon must be achieved during the process of rocking and not a second or so after rocking has been discontinued. The altitude is recorded for the instant that the body kisses the visible horizon at the lowest point of the rocking arc, as in Fig. 2. The only other visual clue as to whether the sextant is vertical is provided by the right angle made by the vertical edge of the horizon glass mirror with the horizon. There may also be some input from the observer's sense of balance and his hand orientation.
A Plea for Simplicity
Authors: Bennett G. G.
Published: November 2009

I believe that it is timely that Dr. B. D. Yallop, Head of HMNAO, has responded to criticisms and the discussions surrounding the inclusion of ‘Sight Reduction Procedures’ and ‘Sight Reduction Tables’ beginning with the 1989 edition of the Nautical Almanac. As my name was mentioned by Dr Yallop, I would like to set out my own views on some aspects of those discussions because I believe that both the ‘theoreticians” and the ‘practitioners” positions have become too polarized.
Target Detection in Radar: Current Status and Future Possibilities
Authors: Li Vincent Y. F. , Miller Keith M.
Published: November 2009

Most of the radar systems used in operating marine vessel traffic management services experience problems, such as track loss and track swap, which may cause confusion to the traffic regulators and lead to potential hazards in the harbour operation. The reason is mainly due to the limited adaptive capabilities of the algorithms used in the detection process. The decision on whether a target is present is usually based on the amplitude information of the returning echoes. Such method has a low efficiency in discriminating between the target and clutter, especially when the signal-to-noise ratio is low. With modern signal processing techniques more information can be extracted from the radar return signals and the tracking parameters of the previous scan. The objectives of this paper are to review the methods which are currently adopted in radar target identification, identify techniques for extracting additional information and consider means of data analysis for deciding the presence of a target. Instead of employing traditional two-state logic, it is suggested that the radar signal should be allocated in terms of threshold levels into fuzzy sets with its membership functions being related to the information extracted and the environment. Additional signal processing techniques are also suggested to explore pattern recognition aspects and discriminate features which are associated with a return signal from those of clutter.
I — R. C. Rawlings
Authors: Rawlings R. C.
Published: November 2009

The application of technological developments to the flight-deck for flight management, navigation and displays has been very rapid and there has been a tendency for parts of the operational system to be improved without evaluating fully their interaction on the flight deck and as between ATC and the aircraft. The Civil Avionics section of Operational Systems Division (FS2) at Bedford has been concerned with the development and investigation of techniques for the integration of this modern equipment into the operational environment of the flight deck of the future, with the overall aim of improving airspace utilization. This will have the potential for reducing delays and saving fuel.
The Prediction of Safety Margins at Sea
Authors: Hagart J.
Published: November 2009

The feasibility of utilizing psychometric tests to investigate accident liability at sea has previously been reported. Analyses of four psychometric tests and ship handling measures, using the statistical techniques of factor analysis and discriminant analysis, investigate the relationship between safety margins and accident liability and support and expand upon earlier conclusions. Evidence is also provided on the validity of a perception-of-risk test for navigators.
The Calculation of Loxodromic Distances
Authors: Sposito Antonino
Published: November 2009

Recent articles by R. Williams and others have indicated an interest in ‘loxodromic distances’, and have described methods of calculation on the spheroidal Earth. However, these methods are not directly suitable for simple hand-held calculators. The following, approximate, methods are therefore suggested.
The Anderson Theorem
Authors: Anderson E. W.
Published: November 2009

In 1835 Gustave-Gaspard Coriolis proved that, if a ‘body’ travelling unaccelerated at a speed v is made to conform to a medium rotating at a rate w, it will be accelerated sideways at vw. Hence air travelling freely, if subjected to the rotation of the Earth's surface, will be accelerated at – 2vω sin ø, –ω sin ø being the rate at which the local surface rotates, with –ω the speed at which the Earth spins and ø the local latitude. (In the diagrams ω is presented as Ω).

2. Coriolis also proved the converse formula from which, if air travels freely over the surface of the Earth, it will accelerate at + 2ω sin ø relative to the local rotating surface. This reversed Coriolis formula happens to be far more important than the original direct formula. It has been applied to long-range artillery, to aircraft using spirit-level sextants, to inertial navigation systems and to the ground tracking of space craft. It has also been applied to forecasting wind speeds.

3. We can handle the duality of Coriolis by a loop diagram as in Fig. 1. The central link shows the direct Coriolis acceleration produced when air travelling freely is forced to conform to the rotating surface of the Earth, The link to the left depicts the reversed Coriolis acceleration which applies to air travelling freely as seen from the local surface of the rotating Earth.
An Inquiry into Simulator Training
Authors: Veenman G. M. , Verhage W.
Published: November 2009

Since 1975 the Royal Netherlands Naval College has operated a bridge manoeuvring simulator for the training of naval officers and petty officers of the deck department. There is a strong relationship between training objectives and performance abilities of a simulator and the way the two match defines the cost effectiveness and the value of simulator training. The training objective being the result aimed at (for a professional watchkeeper) consists partially of a combination of training subjects (things to be learned at the simulator). During 1980 and 1981 R.Nl.N.C. conducted a survey on simulator training subjects by means of an inquiry amongst Royal Netherland's Navy and Merchant Navy officers, marine lecturers (all of Dutch origin) and members of the International Marine Simulator Forum (IMSF). The results form the subject of this note.
Navigation and War
Authors: Jones R. V.
Published: November 2009

One of the essential steps in the operations of war is to know where your enemy is, so that you may either make contact with him or avoid him: the same applies to any friendly force with which you may be operating. And in parallel with these steps you need also to establish your position relative to any natural hazards that you may have either to avoid or exploit. If you can establish the positions of yourself, your friends, the enemy, and the hazards relative to the Earth's surface, you can use the information to control your own movements as you wish; alternatively you can sometimes, by one means or another, directly establish the enemy's position relative to your own and proceed accordingly—a process equally useful in ‘homing’ or evasion.
An Examination of Criticisms of Automatic Radar Plotting Systems and their Advantages in Relation to Manual and Semi-auto Systems
Authors: Herther J. C. , Wylie F. J.
Published: November 2009

The remarks of Mr. Harrison under the above title demand some further comment. One can certainly agree with his substitution of ‘prediction’ for ‘plotting’ but not with his deletion of ‘supposed’. The latter begs the whole question whether the operator will be dangerously deceived and this is far from proven. The latter part of his second paragraph is a generality; there will be many combinations of range and speed in which the result will not be satisfactory.

Mr. Harrison implies, although he does not come right out and say so, that errors arising during ‘classical’ manual plotting are ‘operationally’ acceptable while the errors in automatic plotting are unacceptable. Such a conclusion is illogical if one is willing to concede that any manual plotting procedure can be automated by the use of a digital computer. To examine this assertion in greater detail one may consider the automatic plotter to be made up of a data extraction section and a data processing section.
Plotter Display Philosophy
Authors: Rinaldi R. G.
Published: November 2009

In Captain F. J. Wylie's article, ‘Maritime radar automatic plotter display philosophy’ in the July 1974 issue of the Journal, he states that the IBM Maritime Application Bridge System (MABS) tracks only six targets for collision assessment purposes. This statement is incomplete and I would like to clarify the impression left with your readers.

The IBM MABS tracks up to 21 targets continuously while performing either automatic or manual acquisition. However, since the MABS also prioritizes targets according to threat potential (based on C.P.A. and T.C.P.A.), only the six most threatening are displayed continuously on the alpha-numeric data display and on the PPI. Should the operator wish to obtain data on the fifteen targets of lower priority he can request them in groups of six, in descending order.
The Calculation of Position Line Data with a Computer Calculator
Authors: Podmore Henry L.
Published: November 2009

As a result of the recent marketing of small pocket computers I have found much interest among navigators who would like to use them for working out celestial sights. One computer calculator (the Hewlett-Packard HP-35) in particular appears to be of considerable interest due to its ability to compute trigonometric functions with algebraic logic as well as to store and recall derived intermediate values. Not having been able to find any published work on the use of this type of equipment for the rapid and precise working of sights I have given some thought to the matter and as a result believe the following notes may well be of interest to others.
Dead Reckoning Instrumentation
Authors: Fifield L. W. J.
Published: November 2009

The purpose of this paper, which was presented at the seminar on Coastal Navigation described on p. 448, is to consider the role of ‘dead reckoning’ at the present time, in the context of coastal navigation, and to indicate one or two devices which might alleviate the navigator's task in trying conditions and perhaps improve the accuracy of the result.
VLCC Drift
Authors: Cumming J. A.
Published: November 2009

There has recently been some discussion on the suspected ‘sailing effect’ experienced by ships lying immobilized in a seaway. It was suspected that drift direction may not be truly down-wind, and that on VLCCs in the ballasted condition the sailing effect could be magnified. Few practical data were however available and could easily be spoiled by the effects of current, or become unreliable if established under the influence of light to moderate winds.

An unusual set of circumstances combined on the 3 August 1977 when I was Chief Officer of the Shell tanker SS Lima on her maiden voyage to the Persian Gulf. As can happen early in a ship's life, trouble developed in the engine room requiring the boiler to be shut down for about two days. The first signs of the problem were discovered a few days earlier but the stoppage was planned so that the ship would have plenty of sea room when undergoing repairs. A position off Maputo was chosen, and when within the selected area the ship was stopped and the repairs carried out. During this period the ship was allowed to drift freely and as usual daily positions were obtained at morning and evening twilight and at noon. Figure 1 is an outline chart of the area showing the observed positions. For these times the ship's head is also given, in addition to the associated wind direction and speed.
Crossing Traffic Separation Schemes
Authors: Richardson R. S.
Published: November 2009

The provision of Rule 10 of the 1972 Collision Regulations, that if vessels are obliged to cross traffic lanes they shall do so as nearly as practicable at right angles to the general direction of traffic flow, would appear to be simple enough. Could it be however that in areas of high traffic density, such as the Dover Strait, the theoretical simplicity of the right-angle crossing introduces problems of its own?

Crossing the Dover Strait several times a week, I am constantly alarmed by the apparent lack of regard for Rules 15 and 16 by vessels using the traffic scheme (The rules governing crossing situations and action required by the give-way vessel). I accept that some vessels using the lane believe, albeit incorrectly, that they have the right of way, but feel that a large proportion of these ‘port-side charlies’ are the result of the right-angle crossing.

Because of the pattern of traffic the speed of crossing vessels in the Strait is generally considerably greater than that of vessels using the lanes. Under the present Regulations a situation frequently arises in which a vessel using the lane finds herself as the give-way vessel to another six points or more on her bow. An initial reluctance to alter course by this amount is followed by the thought that there is not sufficient sea-room in which to alter, and the give-way vessel stands on.
The Reduction of Astronomical Sights
Authors: Sadler D. H.
Published: November 2009

The object of this paper is to describe, in principle, a method of reducing astronomical sights, of plotting the resulting position lines and of calculating a position from two or more sights. The method, which is thought to be new, requires neither a calculator nor extensive tables and appears to possess some advantages over more conventional methods. After a general description, and illustrations of two variations, the method is analysed in sufficient detail to indicate that its practical realization, to meet any specific requirement, is a straightforward matter of detailed design.

No attempt is here made to translate the principles of the method into a form for practical use. The paper is mainly addressed to those interested in the theory of astronomical navigation; the description, together with the analysis and the illustrations, is available for use as a basis for a practical method of sight reduction – should anyone consider that there is a requirement! The treatment is intended to be rigorous, though much elementary mathematical detail has been omitted; in a practical application some care may be required near the singularities.
The ‘Manav’ Integrated Navigation System
Authors: Millar I. C. , Hansford R. F.
Published: November 2009

The history of manav goes back fourteen years to 1967 when Esso placed a contract with the Ministry of Technology (mintech) to carry out work to develop a system to assist in ensuring the safe operation of its Very Large Crude Carriers, which were then coming into service. The 1967 era saw much public, governmental and company concern about the stopping and manoeuvring ability of large tankers, particularly when close to shore in estuaries or when berthing.

manav was therefore one of a number of developments or studies initiated by the introduction of VLCCs. Some years were to pass before coordination of the various study results proved possible.

The Racal-Decca (or Decca as it then was) involvement began in 1969 when Esso and mintech decided that an industrial partner should be sought. From the firms approached, the Decca Navigator Company was contracted to undertake a design study. The cost of this study, which started in January 1971, was equally shared between Decca and mintech. This said, it is remarkable how even with a wealth of supporting data having been collected in the intervening fourteen years, the objectives for manav, as set by Decca and mintech, have not radically changed.

The present Department of Industry involvement in funding the sea trial evaluation of manav has its roots in yet a different study; namely the Bridge and Wheelhouse Ergonomics Study, which resulted in the DOI Code of Practice for Ship's Bridge Design.
The English Channel Passage Planning Guide
Authors: Halliwell H. R. W.
Published: November 2009

The first edition of the English Channel Passage Planning Guide was published in February 1981, over a year ahead of the July 1982 routing changes, to familiarize navigators with this new type of publication and to gain experience from users. Edition 2 was published on 2 April 1982 to give advance warning of the full details of the new routing measures; it includes many suggestions from those who answered the questionnaire printed at intervals in Admiralty Notices to Mariners. Even before publication of Edition 1 we had had much useful advice from various professional bodies and, throughout, we have tried to meet the known wishes of those who would be using the Guide.

Format is not the most important feature but it is one on which strong views were expressed. Edition 1 was plainly over-large and unwieldy. We have now reduced the width to standard chart size and completely redesigned the panels to permit folding to a size of about 10 × 14 inches. This compromise between chart and booklet should combine the virtues of a chart (quick correction and filing with other charts where its existence will not be overlooked) and some of the virtues of a booklet (folded, it will not cover the whole of a standard chart which may be in use at the same time).
The Still Undiscovered Origin of Portolan Charts
Authors: Freiesleben H. C.
Published: November 2009

The term ‘portolan chart’ first occurs in Italy in the thirteenth century, not long after this aid to navigation came into general use on board ship. The Italian word portolano, however, can best be translated as ‘pilot book’ or ‘sailing directions’, a different aid to navigation of which one example survives from the fourth century b.c., and pilot books are indeed still published in modern form by all seafaring nations. References by Herodotus in the History make it probable that such documents already existed in his time, and under the name of periplus they continued up to the sixth century a.d.; after which they do not appear again until the golden age of navigation in Italy and Catalonia in the late Middle Ages, apart from some much simpler early medieval types. The portolano or periplus is a description of ports, with information required by the navigator concerning anchorages, dangers threatening landfall and the winds and weather over wider areas. Commercial information was sometimes included, obviously also a matter of interest to the mariner who could read, though it may be doubted if many of them then could.

Italian portolan charts exist from almost the same period as the portolani, both of them denoted by the same word compasso, but while the pilot books have their modern successors the charts were only produced up to the beginning of the seventeenth century and are not really the forerunners of the modern sea chart.
Collision Avoidance Systems and Optimal Turn Manœuvres
Authors: Merz A. W. , Karmarkar J. S.
Published: November 2009

The International Collision Regulations are explicit only with regard to manoeuvre responsibilities. The manoeuvres themselves have been the subject of a large number of technical papers and conferences, particularly during the past 15 years. Nevertheless, although the use of shipboard radar systems has increased during this time, it is apparent from collision statistics and from the variety of published opinions and recommendations that the manoeuvre-specification problem is not considered as solved. In fact, in many cases, recommended turn manoeuvres can actually lead to a cooperative collision, when more realistic turn dynamics are assumed for the ships. The range of conflicting opinions, few of which are based on an analysis of ship manoeuvre dynamics, provides the motivation for the present study.
An Evaluation Trial of the Navigation Accuracy of the L-1011
Authors: Nagaoka Sakae , Yoshioka Eijiro , Muto Tadao
Published: November 2009

The accelerated growth of aircraft operations is causing severe congestion problems at major airports throughout the world and adding heavy burdens on Air Traffic Control which result in traffic delays. Area navigation is regarded as a solution to this problem and a means of more efficient and safe utilization of airspace, both en route and in the terminal area. It is important to evaluate the navigation accuracy of RNAV systems in the Japanese airspace before introducing the concept of Area Navigation technique.
Effects of Measurement Errors in Estimating the Probability of Vertical Overlap
Authors: Nagaoka Sakae
Published: November 2009

The possibility of reducing the current vertical separation minima in order to increase traffic capacity on economical flight levels has been discussed mainly at the RGCSP (Review of the General Concept of Separation Panel) meetings of ICAO. A collision risk model based on the mathematical model developed by Reich (1966) has been adopted for evaluation of safety of air traffic systems under consideration. This collision risk approach requires several parameters which should be estimated from empirical data on navigational errors, traffic dynamics, etc.
A Decimal System of Celestial Navigation Based on the Second
Authors: White K. K.
Published: November 2009

The purpose of this note is to outline a system of celestial navigation which is both decimal and coherent. In a decimal system there can only be one unit, with its decimal multiples and submultiples, for measuring any quantity. It follows that a decimal system of celestial navigation requires one unit for measuring time and one unit for measuring arc. In a coherent system these units must be related by a factor of one.
Navigation and Offshore Oil
Authors: Paton John
Published: November 2009

Commander Paton's paper, which was presented at an Ordinary Meeting of the Institute held in London on 13 March, discusses the implications for navigation and safety at sea of the ever intensifying search for energy resources from the sea-bed. Commander Paton, who is Chairman of IMO's working party on ships' routing, serves at the moment in the Marine Directorate of the Department of Transport. The views expressed, however, are entirely his own.
How Children Navigate
Authors: Spencer Christopher , Blades Mark
Published: November 2009

The paper by Spencer and Blades, both of the Department of Psychology in the University of Sheffield, was presented on 14 March 1984 at an Institute meeting held in London to discuss Psychology and Navigation.

From its earliest moments, the young organism has a need to track and integrate into some scheme of knowledge the location of salient objects and places; and thence to develop navigational strategies for efficient movement through space. In the case of human young, their initially limited mobility constrains the extent of their active explorations, and thus their range of experience; and adult protectiveness (somewhat heightened in the modern, suburban nuclear family setting) continues to limit such explorations even when the child is fully capable of extensive movement round the local area (Pick and Acredolo, 1983).
Navigation Equipment and Training Standards — RIN 85 Conference
Authors: R.M.B.
Published: November 2009

A Conference sponsored by the Institute was held in Cardiff on 2–3 April 1985 to discuss current and future navigation equipment and training standards. A list of the papers presented is given below. The book of papers, entitled RIN 85, is available from the Institute office at a cost of £20 to members and £30 to non-members plus postage.
XIth IALA Conference
Authors: E. R. H.
Published: November 2009

The International Association of Lighthouse Authorities held its eleventh five-yearly conference in Brighton in April 1985, attended by the lighting and buoyage authorities of some 60 countries and by observers from twelve international organizations. The International Association of Institutes of Navigation was represented by its President M. W. Richey and E. R. Hargreaves.
Matthew Fontaine Maury (1806–1873) ‘Pathfinder of the Seas’
Authors: Cotter Charles H.
Published: November 2009

In Virginia's splendid State House at Richmond there stands a marble bust of Matthew Fontaine Maury, one of Virginia's more eminent natural scientists. It might be a matter for dismay for a mariner to read the inscription below the elegant bust, to the effect that this remarkable man owed his fame to having invented an electric torpedo; Maury's fame stands on a much firmer foundation than this! In 1916 the State Board of Education of Virginia set January 14th as ‘Maury Day’ in honour of its celebrated son, and each year on that day Virginian schoolchildren observe and commemorate his birthday. Because of his service to navigation Matthew Fontaine Maury merits the title ‘Pathfinder of the Seas’.
Traffic Lanes and the Collision Regulations
Authors: Kemp-Luck J. G.
Published: November 2009

As a watch-keeping officer on ships daily crossing the North Sea and English Channel 1 was interested to read Commander Paton's paper on ‘Navigation in the English Channel and the Southern North Sea’ in the January 1978 issue of this Journal. Since the introduction of the traffic separation schemes many of us have been concerned about the possibility of an accident whilst crossing the lanes. It is an almost nightly experience to have ‘near misses’ and occasionally more than one ‘near collision’ inside the hour, with people who appear to think that, because they are in a traffic lane and going the right way, everyone else must keep clear of them. No attempt is made to avoid crossing vessels in accordance with the Collision Regulations and, in spite of flashing the warning five shorts and blowing five shorts on the whistle, we often have ships call us to demand we keep out of their way, contrary to all regulations, and frequently forcing us to take drastic evasive action.
DME Glide Slopes
Authors: Proctor J. D.
Published: November 2009

Many runways lack an ILS/GS but have DME on the centre line (e.g. Lagos R/W 19) and DME can provide information in conjunction with the pressure altimeter to define a glide slope. For Lagos R/W 19 I have developed a method of calculation and have tried out the resulting table on two occasions. The pilot not flying the plane consults Table 1 and calls out deviations above or below the glide path (which meets the sloping runway 1500 ft from the threshold for a DC-10).
The Effects of Sonic Boom on the Ecological Environment
Authors: Cerri C.
Published: November 2009

It is expected that the number of military and civil aircraft operating supersonically all over the world may remain the same during the next decade. The problem of sonic boom, which has been by-passed for military aircraft through the assignment of specially allocated ranges for supersonic operation, is still with us and is likely to influence the operation of supersonic transport (SST) aircraft, the Concorde and the Tupolev 144. Concorde is still short of reaching the break-even point, despite the large traffic gain registered on the routes to North and South America. The problem is to get overland routes; the difficulties encountered by the UK in the discussions with India and Malaysia for the establishment of a London–Bahrain–Singapore route are well known.

Before presenting the effects of the sonic boom on the ecology it may be well to summarize the nature and the main features of this phenomenon.

(i) The N-wave signature. A complex body like an aircraft, moving in supersonic flight, generates a pattern of local shock waves which tend to coalesce in two main shock cones, the front (or bow) and tail, as the distance from the aircraft increases. A shock wave is a discontinuity surface for the thermodynamic characteristics of the fluid, the most important being the static pressure jump responsible for the N-shaped pressure signature characteristic of the sonic boom. Other parameters are of minor importance to the environment. A shock signature is denned by the following parameters:
A Modern Collision Avoidance Display Technique
Authors: Riggs Robert F.
Published: November 2009

The marriage of the computer with the collision avoidance (C/A) radar permits a higher order of manœuvrability finesse than is possible with the plotting board. Given the computer as a new tool, the marine systems engineer is faced with the question of whether to attempt a radical improvement in the art of collision avoidance displays, or whether merely to introduce a marginal extrapolation of the existing art. That the first course of action may be necessary is evident from various studies of the modern marine traffic environment; thus a recent study by the United States Coast Guard for the Department of Transportation showed that ‘…the total probability of collision avoidance for this condition [surrounded by a significant number of ships] requires an analytical solution quite different from one which would relate to a sparsely populated area’. Indeed the increase in shipping density, collision rates, speed and size of the newer ships, economic pressures and ecological constraints demand a radically different approach to solving the collision avoidance problem. The marine electronics industry has responded by developing collision avoidance systems of various types. Many of these are relatively straightforward extrapolations of existing art but one at least, the Sperry CAS, goes beyond a simple extrapolation and is a radical departure from conventional practice.
The Loss of Morning Cloud
Authors: Coles K. Adlard
Published: November 2009

On the night of 2 September 1974 Morning Cloud, a 45-ft. ocean racer belonging to the Rt. Hon. Edward Heath, was sunk in a severe south-westerly gale off the south coast of England. The boat was on passage from the east coast to the Solent with an amateur crew for the passage, two members of which lost their lives. Here K. Adlard Coles, a Gold Medallist of the Institute and author of the classic work Heavy Weather Sailing, describes the circumstances in which the disaster occurred as told to him by Don Blewett, who was skippering the boat at the time. Don Blewett's own account appears in Seahorse (Jan./Feb. 1975) the magazine of the Royal Ocean Racing Club.
Education and the Sea
Authors: M'Pherson P. K.
Published: November 2009

Britain is often thought of as a maritime nation. The history books certainly support this thesis with their chronicles of explorations for trade routes, of the development of overseas commerce, which became rather absentmindedly an empire, of the growth of a navy to defend these interests. As an island race which aspired to global enterprise, maritime affairs have never been far from central policy considerations as our livelihood began to depend increasingly on overseas trade routes for food, raw materials and export markets. And along the way we developed merchant and fighting marines that were supreme in their day. From this global perspective we have been and will, probably, always be a maritime nation.
The use of VHF radio to Reduce Uncertainty in Marine Encounters
Authors: Cahill Richard A.
Published: November 2009

The Department of Trade has recently issued a Merchant Shipping Notice (No. 845) entitled ‘Dangers in the Use of VHF Radios in Collision Avoidance’. Though they recognize that ‘the practice of using VHF radio as a collision avoidance aid may be resorted to on occasion, especially in pilotage waters’, the tenor of the Notice seems clearly designed to inhibit the use of this valuable aid to navigation. Their attention seems mainly absorbed by the undoubted dangers attending its haphazard use, which appears to be the salient feature of most of the ‘official’ attention directed towards the use of this device.
Development of Routing in Coastal Waters
Authors: Cockcroft A. N.
Published: November 2009

Traffic separation schemes and other routing measures have now been established in the coastal waters of many countries and new schemes are being introduced each year. Traffic separation was originally intended to reduce the risk of collision between ships proceeding in opposite directions but this paper explains how routing measures are now being used mainly for coastal protection. Improvements in navigational aids may lead to more extensive routing schemes in the future with increasing restriction on the movement of shipping.

The first traffic separation schemes adopted by IMCO (now IMO) in 1965 and 1968 were based on proposals made by the Institutes of Navigation of France, the Federal German Republic and the United Kingdom. In the report submitted to the Organisation by the Institutes in 1964 it was stated that ‘the object of any form of routing is to ease the congestion and lessen the likelihood of end-on encounters by separating opposing streams of traffic …’.
Testing a Modern Strike Aircraft Navigation System
Authors: Collins J. B. V.
Published: November 2009

Mr. Collins, Senior Scientific Officer at A & AEE, describes the testing of a modern strike aircraft navigation system. A brief description of such systems together with an outline of a typical flight profile leads to a discussion of the problems of evaluation and the techniques adopted. The paper was read by Mr. T. O. Coldwell, also of A & AEE, at a meeting of the Institute in London on 18 May 1977 with the President in the Chair.
Traffic Models for use in Vessel Traffic Systems
Authors: Ciletti Michael D.
Published: November 2009

A model is developed for conflicts between ships at route intersections. Quantitative measures are presented for conflict intensity and duration and for intersection capacity. These measures are shown to be related to the geometry of the intersection and to the statistics of the incident flows. An optimum intersection angle is found.
The Estimation of Losses Resulting from Marine Accidents
Authors: Fujii Yahei
Published: November 2009

Studies have already been published on the probability of collision at sea, the effect of darkness and reduced visibility on the probability of collision, and on the distribution of collisions in particular areas. Only Minorsky and Comstock appear to have studied the extent of the resulting damage and sufficient data are not available for detailed analysis.

The establishment and operation of any traffic management system calls for a considerable outlay, so that an objective estimate of the extent of collision losses is often required. Such a cost/benefit survey was carried out by the Japan Transport Economics Research Centre on the assumption that a traffic management system can greatly reduce the incidence of collisions involving vessels of over 3000 g.r.t. Since half the aggregate loss is shown to relate to these large vessels (and considering their increasing capital value), an expenditure of ten billion yen or more (£20 million) over a period of ten years would appear to be cost effective if its primary purpose were to avert accidents to large vessels.
Estimating Speed and Angle of Impact in Collision Cases
Authors: Hellesøe T. Daae
Published: November 2009

When vessels are involved in collision it is usually a result of failure to comply with the Collision Regulations or breach of the duty to exercise good seamanship. If both vessels are to blame they will in most countries be liable for the damage in proportion to their degrees of blame. A vessel claiming compensation for loss and damages will normally have the burden of proving that the other vessel has been negligent, in navigation or otherwise, and to fulfil that obligation the events leading up to the collision must be established as far as possible. For that purpose witnesses are examined and log books and other records on board are studied, although very often the facts are found to be in dispute between the parties involved. The reason may be that the statements of the witnesses are contradictory and impossible to reconcile, even if due allowance is given to the difficulties in making accurate estimates of time, distances, bearings, speed and course alterations. A closer examination of the observations made and the manœuvres carried out is therefore required.