bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Study of a Species of Short-Method Table
Authors: Cotter Charles H. 
Published: January 2010

This paper discusses navigation tables based on the decomposition of the astronomical triangle into two right-angled spherical triangles by a great circle arc extending from the zenith to the meridian of an observed celestial body. In a recent fairly comprehensive study of some thirty short-method tables in which the division of the PZX-triangle forms the principle of construction, nineteen are of the species to be discussed.Following the introduction in 1871 of the first short-method table by Thomson, some twenty years were to pass before any real advance was made in this field. Thomson's table was in fact re-issued by Kortazzi in 1880 and by Collet in 1891, in modified forms, but it was Professor F. Souillagouët of France who is to be credited for introducing something novel and decidedly better than Thomson's table. Unlike the earlier ones it was designed specifically for the Marcq Saint Hilaire method of sight reduction and, in contrast to Thomson's table which was based on the division of the PZX-triangle by a perpendicular from X, Souillagouët's was based on division by a perpendicular from Z.
A Critical Table for Sextant Corrections
Authors: Black A. N. 
Published: January 2010

In a paper under the above title (Journal, Vol. 1, p. 266) J. P. G. Worlledge has made the useful suggestion that sextant certificates should give a critical table for the corrections instead of the present practice of giving the corrections at a few equally spaced readings. Unfortunately the method which he gives of deriving the proposed form from the present form is unsound. The centring error is correctly stated aswhere Z is the sextant reading (the difference between Z and the true angle in this formula is negligible). But part of the centring error is included in the index error, so that to obtain the part of the centring error shown on the certificate the value of C for Z= 0 must be subtracted. This yieldsfor the formula of the correction.
The Navigational Work of the C.S.I.R.O., Australia
Authors: Bowen E. G. 
Published: January 2010

Summary of a paper presented by Dr. Bowen, as President of the Australian Institute of Navigation, to a meeting of the Institute held on 15 June 1951.Accounts of the work described in this paper have been separately published, many of them in this Journal. The paper, therefore, restricts itself to giving a summary of this work, referring the reader to the appropriate literature for further study, and to pointing to some of the outstanding landmarks over the last few years.The work referred to has been carried out by the Radiophysics Division of the Commonwealth Scientific and Industrial Research Organization in Australia and falls conveniently into two main headings, dealing with short-range aids to navigation and with air traffic control. It has been conducted for air navigation, but one at least of the navigation aids developed may find a useful application for maritime use.
II—Traffic Control at the Royal Aircraft Establishment
Authors: Harris G. G. 
Published: January 2010

The traffic control arrangements of the Royal Aircraft Establishment, Farnborough, although they have never been the subject of intensive operational research, but have been derived by a process of steady growth, may be of interest as an example of what can be achieved by good organization on anad hocbasis under some of the most difficult operational conditions.The Royal Aircraft Establishment has an experimental airfield situated in a highly congested area. The London control zone and area is immediately to the north and east, and it is fringed on three sides by civil traffic lanes (Green Airway i in the north and north-west, Red i in the east, and the proposed Red 2 in the south). The Blackbushe circuit of the Ministry of Civil Aviation inter-locks with the Farnborough one in the north north-west, and the circuit of the Odiham R.A.F. airfield, from which jet aircraft are regularly operating, is situated only five miles away in the line of the main bad-weather runway.
I—Elementary Theory Underlying Pressure Pattern Flying Techniques
Authors: Fraser D. O. 
Published: January 2010

Pressure pattern flying embraces a number of air navigation techniques all of which have one common feature: they relate pressure distribution along an aircraft's flight path to that component of the wind which acts at right angles to the aircraft's heading. My intention is to give a brief outline of the theory underlying these techniques.Wind is brought about by horizontal pressure differences in the earth's atmosphere. Air tends to move from an area of high pressure towards an area of low pressure under the influence of thepressure gradient force. The direction of its motion is, however, affected by the earth's rotation in space. Considering this rotation in the horizontal plane only, it is at a maximum at the poles and zero at a point on the equator. At any intermediate point of latitude, the speed of rotation in the horizontal plane is proportional to the sine of the latitude. In the northern hemisphere the rotation is anticlockwise; in the southern hemisphere it is clockwise with reference to outer space.
I—Aeronautical Charts
Authors: Harvey G. A. H. 
Published: January 2010

The mariner has for many years been able to procure charts for practically any waterway in the world and in most cases has the selection of a variety of scales to suit his purposes. The air navigator has not been so happily placed.Shortly after the end of the 1914–18 war the nations subscribing to the International Convention to Air Navigation agreed the need for world cover in aeronautical charts at various scales, but, up to the commencement of the last war, the 1:10,000,000 basic map, for which the French government accepted responsibility, was the only series to reach completion. Various areas were also charted at scales of. 1:1,000,000 and larger.
The Navigational Aspect of Flight Refuelling
Authors: Bennett D. C. T. 
Published: January 2010

British south american airways have recently been carrying out a series of tests on flight refuelling. The first of these tests took place over southern England and were carried out on a scheduled basis at various heights both by day and by night and all proved successful—with the exception of two which were cancelled on account of bad weather, that is, bad weather on the ground and not in the air. The second part of the series has now taken place and consisted of London-Bermuda-London return nights on a weekly basis for a period of three months.The process of flight refuelling does not in fact involve any particular navigational problem, but rather the simple problem of ‘approach’. The aircraft admittedly must intercept, but thanks to the fact that various devices are used for the actual approach of one aircraft to the other the navigational accuracy required for the interception is not at the moment of a very high order.
Navigation in Automatic Flight
Authors: Boxer H. E. C. 
Published: January 2010

At 2215 hours GMT on 21 September 1947 the U.S.A.A.F. All-Weather Flying Centre's Automatic C54 took off automatically from Stephenville, Newfoundland, and twelve hours and five minutes later landed at Brize Norton, England. Neither pilot nor navigator had interfered with the automatic equipment during the entire flight. What, briefly, is the navigation equipment and procedure employed on such a flight?Equipment. The navigation equipment consists of three magnetic heading selectors, two air log units or AMUS and a radio compass which will automatically switch to a number of preselected frequencies.
Microwave Direction Finding for Aircraft Navigation
Authors: Burgmann V. D. , Sheridan K. V. 
Published: January 2010

This paper describes a microwave direction finding equipment and gives the results of flight tests carried out to investigate its possible use for air navigation.The system operates in the 3.2 cm. wavelength band. The aircraft equipment consists of a receiver which sweeps rapidly over a small frequency band, a directional aerial which is scanned in bearing and a cathode ray tube display. The ground beacons are low power c.w. oscillators with an omnidirectional aerial and operate at separate fixed wavelengths to facilitate identification.
The Development of the Aircraft Automatic Radio Compass
Authors: Moon J. H. 
Published: January 2010

The paper reviews some of the major problems which have been encountered in the development of airborne direction finding equipment, and describes, in rather more detail, the latest electrical and mechanical improvements which have been evolved to provide the modern, fast moving aircraft with a more rapid or instantaneous position indication.Various methods of utilizing the information provided by the direction finder are discussed and questions of calibration and ultimate accuracy considered.
Doppler Correction for Surface Movement
Authors: Grocott D. F. H. 
Published: January 2010

A doppler navigation system measures velocity relative to the surface of the Earth. If the surface is moving, as for example when flying over an ocean, the doppler will indicate a false ground-speed and/or drift, according to the direction of surface movement.Trials carried out by the Experimental Navigation Division of the Aeroplane and Armament Experimental Establishment at Boscombe Down show that there is a positive correlation between doppler system error and the surface wind direction when flying over the sea in an aircraft which has an accurate heading reference system. The analysis of all data is by no means complete, but as the spread of errors is so small it is thought that users of doppler navigation systems may wish to see the trend of results and to accept a few simple rules to compensate for the surface movement.The value of the surface movement for a doppler equipment having a 1 percent correction for spectrum distortion is about 3 kt. for a surface wind velocity of 10 kt., 4 kt. for a wind velocity of 18 kt., 5 kt. for a wind velocity of 30 kt. and 6 kt. for a wind velocity of 50 kt. or more. The cardinal rule is that the doppler navigation system will indicate a position upwind of the correct position.Clearly there is little point in applying an across-track correction of say 6 kt.
Priming and Lagging
Authors: Mann E. E. 
Published: January 2010

The term ‘Priming and Lagging’ has been defined in two different ways.The Admiralty Manual of Navigation (1922) defines it as occurring when the resultant of the solar and lunar tides arrives before or after the lunar tide would arrive. This is here called definition A. The Admiralty Manual of Tides (1941) defines it as occurring when the interval between successive diurnal high waters is less or more than the average 24h 50m. This is here called definition B.
I—Strong Winds in the Upper Atmosphere Above 15,000 ft.
Authors: Bannon J. K. 
Published: January 2010

This paper gives a description in very general terms of where and at what seasons may be found the strong winds which occur in the upper atmosphere above 15,000 ft. and discusses briefly the clear air turbulence which is sometimes found in and near these strong winds.Jet streams of temperate latitudes. Navigators are now well aware of the comparatively narrow bands of strong winds, known as jet streams, which occur in the upper troposphere in temperate latitudes. These jet streams, which can stretch for over 2000 miles on occasions, are very variable in position and in strength. It is probably true to say that there is a jet stream with wind speeds exceeding 60 kt. somewhere between Jan Mayen (N. 71°) and Gibraltar (N. 36°) every day, except in quiet summer weather and exceptionally on quiet days in other seasons. Fig. 1, from Durst and Davis shows a typical jet stream; these winds are associated with fronts though the fronts are often of the dry type with very little associated weather. For example, the strong northerly jet stream over the British Isles on 14 November 1949, with speeds of over 150 kt., occurred over a surface anticyclone; it was in this jet stream that the Comet I, on an early flight, experienced very severe turbulence. The level of the maximum wind in these jet streams is about 30,000 ft. though the exact height varies from case to case. Since they are so variable in position and strength the navigator must take particular note of them and a close liaison with the forecaster is clearly essential.
A New History of Navigation
Authors: Collinder P. 
Published: January 2010

Professor E. G. R. Taylor's review, in the April 1955 issue of this Journal, of my book A History of Marine Navigation has passed unnoticed by me during a long absence, and I beg leave to offer a few comments.The reviewer's introductory remark is indisputably correct; the title is not an adequate one. The Swedish title, literally translated, is From Noah's Dove to the Gyro-compass: navigational art, ancient and modern. In the earlier chapters I have not followed a chronological sequence but rather proceeded in order of the degree of complication of the methods used. In the later part of the book, I admit that there are many lacunae. However, as the reader will find, there was no ‘final jump’ to electronic navigation; there were several stepping-stones, viz. wind- and current-charts, the gyro-compass, radio-location, and echosounding.
Spheroidal Sailing and the Middle Latitude
Authors: Sadler D. H. 
Published: January 2010

The standard formulae, assuming a spherical Earth, for converting distance on a rhumb-line track into differences of latitude and longitude are:where C is the course and α is known as the middle latitude. It is approximately the mean latitude when both points are on the same side of the equator; tables of the correction to be applied to the mean latitude to give the middle latitude are given in most collections of nautical tables.
Navigation during the break through the Channel in 1942
Authors: Giessler Helmuth 
Published: January 2010

Captain Giessler, who is now assistant to the director of the Auschuss für Funkortung (the German association concerned with radio navigation) was navigating officer of the Scharnhorst when that ship with the Gneisenau and Prinz Eugen broke through the English Channel in February 1942. It is thought that this account of the operation will interest many navigators, even though it is not entirely navigational in content.Towards the end of 1941 the repairs to the battle-cruisers Schamhorst and Gneisenau, lying at Brest, and to the heavy cruiser Prinz Eugen were already so far advanced, in spite of continual very heavy air attacks, that a decision had to be made as to the further use of these forces.
II—The Use of the Flight Log
Authors: Wright E. R. 
Published: January 2010

The use of the Decca flight log is most simply illustrated by referring to an actual flight, in this case on a Viscount service out of London Airport.Fig. 1, which is a section from the chart roll used on a recent service, shows the London Control Zone chart. Take-off was from runway 2 8 RIGHT on an IFR day and the outward bound clearance was Chertsey 2000 ft., Dunsfold 3000 ft. with a radar climb en route to Seaford. At the time when the pilots are fully occupied with after take-off drills, r.t. &c., and maximum concentration on instrument flying is necessary, a quick glance at the flight log is all that is necessary to check that the aircraft is on track. At this stage, in the event of radar failure, an accurate position of the aircraft can be passed to air traffic control at any time it is requested, and ‘flying well right of the centre line’ and subsequent resumption of track is easily effected.
A Modern Flight Instrument System
Authors: McKinlay W. H. 
Published: January 2010

Almost all the long-range civil transport aircraft entering service during the next few years will be equipped with some form of instrument system. It is proposed to describe here some aspects of the developments which have been embodied in one such system, the Smiths Flight System, and to indicate its scope when applied to the operation of such aircraft.Since the war the operation of a high-performance transport aircraft on congested and competitive routes has become an increasingly complicated process. With the advent of the gas turbine, cruising speeds have doubled, and at the same time there has been a tendency towards higher standards of economy and safety. The development of the air traffic control system has brought about a demand for greater precision in navigation, and in the most congested areas by far the greatest number of flights are conducted under instrument conditions. Meanwhile, aircraft have also become more complex, and the pilots themselves are often expected to monitor the operation of the controls and instrumentation associated with the engines, electrics and pressurization as well as carry out the navigation. This extra work has had to be undertaken without any relaxation of the general vigilance which constitutes good airmanship.
Position Finding in Captivity
Authors: Beeham P. 
Published: January 2010

In December 1940 some 500 captured allied seamen, including the author, were transferred from a German commerce raider to an ex-Norwegian tanker under the command of a German prize crew, with the original crew still aboard. The ship was in the Southern Indian Ocean—in about S. 32°, E. 70°—just cruising about aimlessly; apparently awaiting orders to proceed. The captured Chinese and Indian ratings were accommodated aft somewhere, the shipmasters and passengers were housed amidships; and the rest were forward.This vessel was very effective for the purpose to which it was being put as it was easy to position machine guns to cover all ways of approaching the midship house; in particular the fore part of the bridge was a solid wall right up from the foredeck to the high dodgers. Nothing could be seen of those on watch and no bells were struck, so that the officer prisoners were denied the sight of anything which might help them to guess what was happening, and any sound to give them an idea of the passage of ship's time.
The Region of Collision
Authors: Slater W. T. 
Published: January 2010

Captain Wylie's paper on ‘The Region of Collision’ raises some interesting points but if one accepts the view that graphing of some sort is not wholly ‘academic’ the writer feels that there is an alternative graph which Captain Wylie has not mentioned and is worth considering.As Captain Wylie has shown, the time-distance plot gives very little useful information except that it does keep prominently in mind the distance between the two vessels. The time-bearing plot is much more informative as to the element of danger present in the situation but if the time-bearing is the only plot kept then the fact that it shows no distance between the vessels is a serious disadvantage. The writer suggests that it might be worthwhile considering the advantages of plotting change of bearing against distance between the vessels, especially if this is done on a graph having precomputed curves for various minimum separations between the vessels. The sort of graph obtained is illustrated in Fig. 1 which shows a family of curves for vessels maintaining steady courses and passing at minimum separations of ½, 1 and 1½ miles, curves A, B and C respectively, on the assumption that plotting is begun from the point where the vessels are four miles apart.
D.f. Loop Errors due to Heel
Authors: Chichester Francis 
Published: January 2010

Yacht and other small-boat navigators must often wonder what error in a d.f. loop reading on a radiobeacon may be due to heel. The error is in fact quite small, the maximum for a 25° angle of heel being 2°.8 when the bearing is quadrantal to the boat's heading, i.e. when the relative bearing is 45°, 135°, 225° or 315°. When the relative bearing is 0, 90°, 180° or 270°, i.e. when the beacon is ahead or astern or abeam, the error is nil.Table I gives corrections to the nearest ½ degree, to be applied to the relative bearing of a beacon for 15° and 25° of heel. It makes no difference whether the boat is heeled towards or away from the beacon.
A Series of Marine Data Systems
Authors: Mackay I. S. S. 
Published: January 2010

This paper describes a series of data handling systems, termed MARIDAS, which would cater for various maritime problems and situations. Eleven specifications have been prepared, of which three, those for hydrographic work, harbour and pilotage, and merchant ships, are reproduced as Annexes here. A version of the paper has appeared in naval publications with restricted circulation.In the past decade various navies have introduced electronic data processing to ease the strain on ship captains and their officers in order to increase their efficiency. The need is urgent as the quantity of information now available from the many sensors has grown so remarkably, and the speeds of aircraft and targets have increased to such an extent, that human reaction and ability is fully extended. However, the thought processes in all the operations which have to be performed have remained the same. These processes are largely related to the solution of trigonometrical or triangulation problems: Spherical, for astronomical or satellite navigation; Plane, using distances and angles for geographical or relative position problems and speeds and angles for relative velocity problems, avoidance of collision and intercept.
Area Navigation and the Relationship to Terminal Area Capacity
Authors: Winick Alexander B. 
Published: January 2010

An area navigation capability can be of considerable benefit to users as well as providers of ground facilities. A.T.C. radar terminal service and area navigation utilizing cockpit pictorial displays are complementary from a total system viewpoint. Pictorial displays, coupled with digital computers capable of storing navigation information, will greatly reduce pilot workload. Optimum usage of A.T.C. radar service and cockpit navigation will provide maximum redundancy at least total cost and reduce controller workload.Pictorial computer procedures will have many applications of benefit to high density terminal areas, such as (1) departure paths from a satellite airport, (2) descent paths from high altitude to a terminal area, (3) missed approach patterns, (4) approaches to satellite airports, (5) simplified holding procedures, and (6) discrete paths for descent corridors. Procedures are expected to be developed as a result of a full-scale Federal Aviation Administration operational programme for selected en-route and terminal areas permitting use of area navigation facilities, using F.A.A., airline and general aviation aircraft in a live A.T.C. environment.
The Metrication of Navigation
Authors: Turner Ronald 
Published: January 2010

Since government and industry have officially accepted the introduction of the International System (S.I.) Units for all forms of measurement it is relevant to examine the implications of this for marine navigation.The present situation. Marine navigation is no different from many other fields in that a proliferation of units is used to measure the same dimension and, moreover, these units have no systematic relationship to each other. In this respect length is the worst offender: we measure heights in feet, depths of water in fathoms, distances in cables or nautical miles and moreover these nautical miles may be British standard, International standard or those precisely determined by latitude.