bluuebunny/crossref_metadata_2025_split huggingface dataset:
S.S.T. Simulation Exercises
Authors: Schmid H. 
Published: January 2010

The S.S.T. simulation programme of the F.A.A., already in progress since May 1963, aims at determining system requirements both ground and air in the period 1970–75 and, as a future project, in the era 1975–80. In this context, air operations involving the following types of aircraft are under study:(a) Current and future military aircraft with supersonic speed capabilities;(b) Concorde-type operations;(c) Mach 3 or mach 2.7 civil transport operations.Since the start of the S.S.T. simulation programme, six studies have been undertaken, each of an average duration of 6 months.From May 1964, a S.S.T. flight deck simulator (modified DC-8 simulator), located at the N.A.S.A. Research Center, was linked with the A.T.C. simulator at N.A.F.E.C., for communication of positional data (digital, including S.S.R.) and voice information, and thus formed part of the traffic sample under study, i.e. one aircraft among 108 others that can simultaneously be simulated at N.A.F.E.C.Whilst previous exercises concentrated on terminal area (T.M.A.) requirements, the exercises in progress in July 1966 were designed to examine extended T.M.A. and en-route operations in the early 1970s, with Concorde and mach 3 or mach 2.7-type S.S.T.s flying in or through a mixed environment of subsonic traffic. Amongst other parameters, a variety of geographical zones, air traffic control centres, T.M.A. control units, route network configurations in the New York, Boston, Cleveland and California areas, were simulated with a view to determining the impact of specific regional terrain and traffic conditions.
British Mathematical Biobibliography
Authors: Wallis P. J. 
Published: January 2010

Thepublication of a new impression of Professor E. G. R. Taylor's first volume ofMathematical Practionersso soon after the appearance of her second volume makes it a particularly appropriate time to take stock and consider the next steps. Despite various criticisms, some of which will be discussed below, all reviewers agree that her volumes mark a great advance in this field and will be of ‘immense service to scholars’. Our debt to the author is all the greater when we realize that these books followed on a whole series of standard works in her own subject of geography, and that she was neither a mathematician nor a bibliographer. The best tribute to Professor Taylor is to continue the work recorded in these two volumes, but there are few who have the detailed knowledge and expertise to follow her in such a wide field. This article will, for example, offer little comment on instrument-makers who form such a large section of herpractitionersand who left records of their work in museums and private hands all over the country; here we shall be much more concerned with the written work, with the bibliography of the subject.Reviewers of her volumes have found it difficult to define the practitioners of whom she wrote and to decide in what sense they differ from mathematicians in the normally accepted sense of this country or overseas.
I—Doppler Navigation in S.A.S.
Authors: Pedersen Einar S. 
Published: January 2010

In order to find out what type of doppler navigation equipment would be most suitable for the S.A.S. fleet of DC-8s it was decided to start a programme of doppler evaluation in Spring 1958. The doppler evaluation programme included evaluation of doppler equipment from Canadian Marconi, General Precision Laboratory (G.P.L.) and Collins Radio Company.The programme started in April 1958 with evaluation of Canadian Marconi doppler equipment. The evaluation period lasted six months. In April 1959 evaluation of Collins and G.P.L. doppler equipment started and lasted for eight months. In March 1960 evaluation of Collins and Canadian Marconi doppler equipment started and is still in progress. And finally by the middle of May 1960 evaluation of G.P.L. Radan 500 was in progress.
II—An Evaluation of the Marconi AD 2300
Authors: Brunt W. E. 
Published: January 2010

When, in 1958, B.O.A.C. undertook to evaluate the Marconi AD 2300 doppler navigator, the exercise was planned with great care. The aim was to determine the performance of the system in quantitative terms, and to express the results so that their operational significance was clear.In preparing this evaluation, three objectives were stated, as follows:(a) To obtain quantitative data on the performance of the AD 2300, considered as a measuring device, in terms of accuracy, consistency and reliability.(b) To obtain qualitative information on the optimum methods of system application, by reference to observer reaction.(c) To introduce the doppler system in operation to a wider selection of B.O.A.C. flying staff, in order to develop a body of informed opinion.It is the first of these objectives with which this paper will deal.
Determination of Position on the Earth from a Single Visual Observation of an Artificial Satellite
Authors: Scott W. A. 
Published: January 2010

While engaged in the observation and prediction of the position of Sputnik I, it was realized that, if a reliable orbit were available, and an observation of the satellite against the background of stars were made to a precision of about 0°·1 and timed to about 0·2 of a second, then the position of the observer could be determined to a precision sufficient for most navigational purposes. The following account demonstrates how this has actually been done from a single visual observation of the American Balloon Satellite Echo I (designated 1960ι1).Principle of method. The direction in which an observer on the Earth's surface sees an artificial satellite at any instant differs from that in which it is seen by any other observer and from that in which it would be observed from the centre of the Earth. The amount and direction of the parallactic shift can be determined from the comparison of the direction of observation with that calculated from the geocentric ephemeris of the satellite; and the position of the observer on the Earth's surface can be uniquely calculated from this parallactic shift. Only a single observation is required, without reference to the vertical.
A Further Note on Seaborne Traffic
Authors: Oudet L. 
Published: January 2010

The Channel Bridge. I am happy to report that Commandant Poll's admirable scheme for traffic in the Strait of Dover (p. 75) has provoked, at least on paper, a most interesting reaction. Commandant Poll brought out his plan in February 1960. In March the Compagnie Française d'Entreprises consulted me about a scheme for a Channel Bridge which they had drawn up in conjunction with the English firm of Dorman Long and the American Merrit-Chapman and Scott Company.As seamen we hold no brief either for a bridge or for a tunnel; our personal interest can be no more than an expression of our attitude as citizens of our respective countries. But as soon as the matter was brought to my attention I realized that there can be no two opinions about our professional attitude: we must first make sure that the bridge will neither endanger nor delay shipping, and when we are satisfied on that point, we must do nothing to hinder the realization of a project which cannot fail to improve international relations in our ageing West.How are we to make sure of our necessary condition? The first and most important step is to establish the one-way routes detailed by Commandant Poll, and to see to it that the arches which cross them are as wide as possible. The normal span, 200 metres from pier to pier, with a clearance of 53 metres, is suitable only for small ships.
Aircraft Navigation by Satellite
Authors: Myers H. A. 
Published: January 2010

Aircraft navigation using doppler and orbital information transmitted from a satellite is shown to be feasible, at least in a limited sense, using the least squares, differential correction method of computation. If sufficiently accurate velocity information can be provided, this approach could yield positions for long-range aircraft that are an order of magnitude more accurate than have been achieved with other world-wide, all-weather, all-altitude systems, such as doppler and inertial navigators.The least squares, differential corrections solutions for both position and velocity do not converge for reasonable initial errors. Therefore, accurate aircraft velocity components, such as those provided by a doppler navigator, must be known. For one-knot velocity errors the position of a 500-knot aircraft can be determined to one-half nautical mile or better for latitudes up to 70 degrees. Several-knot velocity uncertainties result in position errors of a few nautical miles.The position accuracies for supersonic aircraft are limited by the velocity accuracies achievable with the best doppler navigators. Computational methods that yield velocity as well as position, so that the satellite system would not have to depend so much on another navigation aid, would be most desirable.
The Mathematics of Collision Avoidance in Two Dimensions
Authors: Hollingdale S. H. 
Published: January 2010

The geometry of collision at sea has been dealt with in a series of papers published in the Journal, notably by Sadler (10, 306), Calvert (13, 127), Garcia-Frias (13, 316) and Morell (14, 163); and a further contribution from Calvert (to which reference is made in this paper) will be published in the next number.The object of the present paper is to examine whether anti-collision manœuvres, here considered for the case of two craft moving in a plane, can be formulated on a rigorous logical basis. If they can, then clearly a proper appreciation of the geometry of collision is a prerequisite to the formulation of any rules and regulations. In this important paper the author gives a precise and complete answer to the basic problem, and he proves mathematically that it is the only answer. As Dr. Hollingdale freely acknowledges, however, this can only be a contribution to the study of the collision problem, which involves innumerable operational factors in addition to the geometry of the situation.The convention adopted in the present paper is that each craft shall manœuvre so that if the other craft stands on, the sight line always rotates in the anti-clockwise direction. The analysis shows that a simple set of manœuvres can in fact be developed on this basis and that such manœuvres are the only ones that, geometrically, meet all the specified requirements. In all cases the combined manœuvre converts a collision situation into a ‘miss’ of at least a specified magnitude.
The Long-term Plan for Air Traffic Control
Authors: Hunt V. A. M. 
Published: January 2010

This paper by the Director of Control and Navigation at the Ministry of Aviation, reviews the present state of planning for air traffic control in the United Kingdom. It indicates that whilst progress is evolutionary and continuous, big steps take place approximately every ten years. The author concentrates on four principal facets of air traffic control which cause the most acute problems, namely the medium-haul operations in densely populated areas; the terminal problem; long-distance operations over the Atlantic; and low-level, short routes in the south-east of England.The paper outlines the basic air traffic control system of the future and indicates the ways that data processing and radar may be used. It makes a short reference to the specific problems of the supersonic aircraft and concludes by referring to two principal experimental projects now in hand to enhance our knowledge of data processing with respect to air traffic control.
The Planning of Runway Layouts as Affected by Weather
Authors: Jacobs L. 
Published: January 2010

A method is presented for quick calculation of the frequency of cross-wind components which limit the landing of aircraft on runway layouts at aerodromes ánd for deriving the best runway layouts for a site with a known or deducible wind distribution. The method depends on some initial study of the relevant wind rose but an exact solution is obtained by the application of the empirically derived formula nv = Ce–bv2 where nv denotes the percentage of time that a wind exceeds a velocity v and C and b are constants for a given site. This formula was originally verified only for the British Isles but later it has been found to be valid elsewhere where there is a wide range of wind speeds. Allowance can be made in the calculations for bad weather, e.g. dense smoke or low cloud approaching the aerodrome from certain directions, for use of one end only of a runway and for a permissible tail wind component.The paper was originally issued in 1944. The method described has not been changed and the description is only slightly modified. The chief changes are the substitution of numerical integration using Meteor computer instead of the original planimeter measurement of curves and the introduction of the ‘bisector’ correction. Certain details of the calculation notably four-figure tables of L(i) (eqn (5)) and of the bisector correction, a complete example of the method, the way to remove ‘bias’ in wind summaries and the derivation of the bisector correction are given in a duplicated Addendum to this paper which is available on request from the Institute.
A New Altimeter Display
Authors: Melchior F. G. 
Published: January 2010

Before commencing an analysis of the subject matter at hand, it will be as well to present some definitions which we have adopted, in our own work, even if they represent in part arbitrary interpretations of our own.(a) Pressure altitude is, of course, nothing but barometer pressure at any given elevation, converted into equivalent altitude (feet) units; hence a variable.(b) Sea-level in connection with altimetry is only a theoretical reference value which does not necessarily conform with mean-high water; in terms of pressure altitude, needless to say, it is also a variable.(c) True altitude (above sea-level) cannot be obtained with satisfactory accuracy by merely correcting for sea-level barometer pressure. On the other hand, we must dispel the notion—not uncommon—that one can obtain more accurate altitude values by correcting for temperature and humidity at a particular flight level. There are such things as inversions and convection currents; we do not need cold weather to have a high barometer, and sometimes it is warmer a few thousand feet up than at ground-level.(d) Performance of pressure instruments is properly expressed in parts of the pressure range—not in per cent of altitude—and the reason is simple: at, say, 60,000 ft. you have about 16 times as may feet per unit of pressure as at sea-level.(e) Sensitivity is—technically speaking—the smallest part of the pressure range that will produce a measurable response.
Prediction of Wave Characteristics Over the North Atlantic
Authors: Darbyshire J. 
Published: January 2010

This paper develops a method for the prediction of wave height, period and direction on a 200-mile grid over the North Atlantic Ocean, using a wave spectrum technique. The method could be useful in conjunction with optimum ship routing across the ocean.AS discussed recently by Hanssen and James, ship routing across the ocean, using the optimum route with respect to weather conditions, is now becoming a practical possibility. One essential requirement is to predict the wave heights and lengths over all parts of the area concerned. This would require first, of course, a forecast of the wind conditions. At present the Meteorological Office issues prognostic weather charts 24 hours ahead and wave predictions must be tied to them. Wave conditions are not determined instantaneously by the weather conditions at a given time, but tend to be an integration of the weather conditions over two, three, or even more days before and so wave predictions 24 hours ahead are likely to be more accurate than the wind forecasts.
A Quantitative Analysis of Avoiding Action
Authors: Hasegawa K. , Kasahara K. , Yamazaki Y. , Kai Y. 
Published: January 2010

There have recently been various investigations of avoiding action when a ship is navigating by radar. The present paper attempts a numerical analysis of the changes in the apparent motion of the echo of the other vessel on the radarscope when both vessels alter course and speed simultaneously.First we consider the case where the echo of the other vessel is approaching the centre of the radarscope—that is the vessels are on a collision course.In Fig. I AOB represents a velocity triangle:OA = own vessel's course and speedOB = other vessel's course and speedAB = other vessel's relative course and speedWhen both vessels alter course, by Δα1 and Δα2 respectively, the velocity triangle becomes A′OB′ and A′B′ represents the new relative motion of the other vessel. If the triangle A′OB′ is rotated through Δα2 about O, and OB′ coincides with OB, the triangle is represented by BOC and < CDA′ = Δα2. The change θ in the other vessel's relative course caused by both vessels altering course by Δα1 and Δα2 respectively is therefore:Now φ can be shown to satisfy the equation:
Strapped Down Inertial Navigation Systems
Authors: Collinson R. P. G. 
Published: January 2010

The heart of an inertial navigation system is the Inertial Measuring Unit (I.M.U.) as this carries out the fundamental tasks of measuring the vehicle acceleration and providing a spatial reference. The I.M.U. thus determines the system performance and accuracy; it also accounts for about two thirds of the initial cost of the system and is a major factor in the cost of ownership.Up to now the majority of IN systems have used a stable platform I.M.U. where the gyros and accelerometers are mounted on a gimbal suspended platform which is servo controlled from the gyros. This has greatly eased the task of developing suitable gyros of the required accuracy, as the gimbal stabilization system isolates the gyros from the angular motion of the vehicle and greatly simplifies the subsequent computation in terms of axis transformations; it provides a direct read out of the euler angles—heading, pitch and roll. However such a system is inevitably mechanically complex and its ultimate reliability is constrained by such components as slip rings, servo motors, synchros, resolvers, encoders, gimbal bearings &c.
The Use of a Computer for Correcting Ocean Soundings
Authors: Sherwood Ruth 
Published: January 2010

The velocity of sound in water is a function of temperature, salinity and pressure. When an echo-sounder is used to make depth measurements, the time taken for a pulse to reach the ocean bed and return is measured. The machine is set to a standard sounding velocity, usually 800 or 820 fm/second (1463/1500 m/sec), and a nominal depth is recorded. This depth should then be corrected for the properties of the water. The ‘Tables of Velocity of Sound in Pure Water and Sea Water” by Matthews are commonly used for this purpose. Matthews compiled his tables using soundings taken by a number of research ships all over the world. He divided the oceans into 52 areas, and for each area calculated a set of depth corrections from 200 m to the ocean bottom. Since the tables were published more accurate measurements of velocity as a function of temperature, salinity and pressure have been made. There are also many more observations than were available when the tables were compiled. However, as these tables are in general use, no attempt has been made in this paper to change the corrections, and any computer results are therefore no more accurate than the tables.When correcting depths manually aboard ship, the following procedure is followed. The depth on the echo-sounder is noted and entered into a log book. The position of the ship is known using some standard method of navigation such as satellite, Decca, Loran or radar.
Four-Point Mooring
Authors: Lees K. G. 
Published: January 2010

H.M.S. Reclaim was built in 1948 by Simons & Co. of Renfrew as a salvage ship of the King Salvor class but altered before completion for her role as a deep diving vessel. She established world deep diving records in 1948 (536 ft., 163 m.) in Loch Fyne, the diver wearing a standard diving dress and breathing a mixture of oxygen and helium, and in 1956 (600 ft., 183 m.) off Norway. In 1964 she carried out a series of dives to 600 ft. for one hour, off Toulon, the divers wearing lightweight self-contained equipment. In 1950 she located the sunk submarine Truculent in the Thames estuary and in 1964 the submarine Affray, when underwater television was used for the first time. In 1966 she recovered a crashed Viscount aircraft in the Irish Sea. Reclaim is now engaged in trials which will eventually permit diving for prolonged periods to 1000 ft., and therefore anywhere on the Continental Shelf.Two divers are lowered to the sea-bed in a submersible compression chamber equipped with underwater lighting and television and in telephonic communication with the ship. While one diver swims out of the chamber to undertake the required task the other acts as attendant. The chamber when hoisted aboard under pressure is locked on to another chamber in the ship's hold, where the divers carry out the process of decompression which may take several hours.H.M.S. Reclaim encounters some unique navigation and seamanship problems when engaged in deep diving.
The Reverse Stopping Ability of Supertankers
Authors: Tani H. 
Published: January 2010

The question of the reverse stopping ability of a ship is well known but is yet a fresh problem. Until about twenty years ago the distance required to stop a.ship from a service sea speed ahead by using her engines full astern with helm midships was comparable to her advance while stopping with helm hard-over. However, at present this head reach of a 100,000- d.w. supertanker may range from 10 L to 15 L while her advance with maximum helm angle might only be from 5 L to 7 L. At first sight this appears to be a surprising phenomenon, but it is little wonder since the mass of the ship and hence the inertia increases with the cube of her length, while the total resistance of her underwater hull only with the square of her length.The question of stopping very large supertankers is one of some significance both from the viewpoint of preparing to pick up a pilot, anchoring, berthing, or similar everyday operations and of avoiding collision or grounding in an emergency.
Handling Large Vessels in the Port of Hirohata
Authors: Onishi T. 
Published: January 2010

Professor Tani's paper (p. 119) describes recent work on the problem of calculating head reach for mammoth ships of one kind and another. Handling these vessels in confined waters and bringing them alongside the berth also poses particular problems to pilots. This paper illustrates some of these problems, which of course differ to some extent for each port, by describing the pilotage procedures used in one of the new Japanese ports built to accommodate very large vessels.1. The inland sea and large vessels. The Inland Sea has a coast line of about 4272 kilometres and covers an area of 18,000 square kilometres, equal to that of Lake Ontario. The distance from east to west is about 260 miles and the broadest part from north to south is about 30 miles wide. Navigable channels or waterways for large vessels run in all directions.