bluuebunny/crossref_metadata_2025 huggingface dataset:
Precise Underwater Navigation
Authors: Cestone Joseph A.
Published: January 2010

In this paper, which was presented at the Quadripartite Meeting of the Institutes of Navigation in Rome, 11–14. May 1970, the author describes the precise acoustic navigation systems designed for use with submersible vehicles as distinct from typical cruising submarines. With recent technical advances in position finding a whole new range of underwater tasks for the submersible has been opened up.
Manning Reductions and the Cost of Navigation
Authors: McKenzie J. S.
Published: January 2010

This paper looks at the cost of navigation and endeavours to establish a relationship, of the type studied by Professor H. Benford, between manning and its associated cost in British shipping. Certain assumptions are made concerning the capital investment and operating costs for navigation equipment and from these the progressive savings are estimated for minimum manning and an unmanned bridge. Captain McKenzie is Managing Director of Marine and General Computer Consultancy (I.O.M.) Ltd.

After some considerable investigation into the costs of marine equipment and accommodation it has been found that there is the greatest difficulty in establishing a base cost on which to examine possible reductions. Equipment, salaries, accommodation and fringe benefits vary so much from company to company and ship to ship that any comparison is meaningless. Thus we must consider some hypothetical ‘standard ship’ and define fairly closely what equipment is already on board and the average salary for staff or crew members. It seems reasonable to look at a modern ship equipped with all the devices which an up-to-date shipowner considers necessary for her operation and—more important—her safety.
The Simple Logic of Radar Avoidance Action
Authors: Inglesby J. V.
Published: January 2010

In this paper the basic principles of avoidance action are developed. It is shown that a unique set of rules exists which will guarantee the safe passage of converging aircraft; when two are involved, if either, or both simultaneously, act according to these rules, it is impossible to have an accident whatever the situation. (This assumes inerrant assessments on the part of Controllers, and it also assumes that the uncontrolled aircraft continues on course.) The rules are consistent with the Rules of the Air. Past attempts to formulate rules are compared.

The action taken by an aircraft in flight to avoid coming dangerously close to some other nearby aircraft we call ‘avoidance action’. This action may be made by the pilot should the other aircraft come within his field of view, or if ground controlled, it will be initiated by the Radar Controller. The pilot works to the Rules of the Air and the Radar Controller works to them whenever it is possible for him to do so. The Rules of the Air do not always help the Radar Controller because, in every case, except for two aircraft approaching each other head-on, one or other has the right-of-way and ‘an aircraft which has the right-of-way shall maintain its course and speed.’ This means that an aircraft which has the right-of-way must not take avoiding action. The object of this paper, therefore, is to attempt to propose a set of avoidance action rules which will assist Radar Controllers in their task.
Why an Institute of Navigation?
Authors: Hugon P.
Published: January 2010

In this paper, which was originally published in Navigation, Paris, July 1970, the distinguished General Secretary of the French Institute of Navigation, Professor Pierre Hugon, a Gold Medallist of this Institute, examines some of the premises adopted by M. W. Richey in his paper on the Institutes of Navigation presented to the Australian Institute of Navigation in October 1969 (this Journal, 23, 99). It is interesting to note the extent to which the conclusions in these two papers differ in emphasis.

Following in the footsteps of my friend Mr. M. W. Richey who, at the twentieth anniversary meeting of the Australian Institute of Navigation in Sydney on 10 October 1969, presented a remarkable address on ‘The Institutes of Navigation in the 70's’, I am impelled to state the position of the sister Institute in France by examining once again the very principles of such an undertaking and discussing its future character. This unpremeditated essay concerns a duty and a faith which, though they must not give way to doubt, are nevertheless open to question.
Traffic Separation in the Dover Strait
Authors: Richey M. W.
Published: January 2010

The recent collisions in the English Channel and the Dover Strait have caused a great deal of public disquiet in this country and the United Kingdom's Department of Trade and Industry's Safety of Navigation Committee were invited to discuss what, if any, measures should be recommended to Imco to improve the routing system in the Strait. The Institute of Navigation, with its French and German counterparts, was largely responsible for the introduction of the routing scheme in force in the Strait and has since its introduction in 1967, by means of a series of international working groups, kept a watchful eye on how things were going, and on occasions made recommendations for its improvement.
Collisions in the Dover Strait
Authors: Black A. N.
Published: January 2010

In the October Journal, p. 538 and Table I on p. 539, it is shown that the number of collisions per fog day (abbreviated below to c/fd) has fallen by some 20 per cent since routing was introduced in 1967. It is not legitimate to assume without further argument that this is a case of cause and effect.
‘Mammoth Vessels and Coriolis Force’
Authors: Lewison G. R. G.
Published: January 2010

Mr. Anneveld's paper (24, 50) would have us believe that the effects of coriolis force on a ship may become appreciable as ship size increases. It is true that the drift angle does increase as the ship's size increases, because the coriolis force given by equation (1) increases as (length)3·5 and the resistive forces increase as (length)3 (on the assumption of geometrically similar ships and Froude scaling). However there is a fundamental flaw in his argument because equation (2) only applies to a vessel with zero forward speed. Moreover the effect of coriolis drift will also be to induce a yaw angle on the ship (because the centre of pressure is forward of the centre of gravity, where the coriolis force may be assumed to act) and this will automatically cause the helmsman or autopilot to apply starboard rudder in the northern hemisphere. This will immediately produce a force on the ship in the port direction, i.e. opposing coriolis force.
Visual Factors in Aircraft Navigation
Authors: Heap E.
Published: January 2010

In navigating an aircraft visually over terrain the chance of successfully reaching the destination greatly depends upon the human element together with the visual aids provided. Some visual factors are studied in detail in this paper, particularly the detection and identification of ground features from the air. The suitability of various identification points for use as visual fixes is assessed quantitatively and the interaction between navigational accuracy and feature detection is discussed. The effects of visibility, speed and search are also studied. Visual aids considered include different scale maps, heading information, and fixed, zoom and search optics on television. A number of navigational tasks are covered, from following line features to direct cross-country tracks. Successive visual up-dating of a mixed manual and automatic navigation system is then assessed theoretically.
Some Remarks on the Distribution of Aircraft Track-keeping Errors
Authors: Abbott M. R.
Published: January 2010

Wing Commander Anderson has drawn attention to the fact that the distribution of the larger navigational errors is frequently observed to be non-gaussian in character. He raises the point whether this can be accounted for by the generation of such errors in succession, rather than simultaneously. The successive generation of navigation errors arises through the error incurred on a particular leg being distributed about a mean which is dependent on the error up to the end of the previous leg.
Distribution of Jet Streams in the North Atlantic, Europe and the Mediterranean, 1957–8
Authors: Crossley A. F.
Published: January 2010

From an inspection of upper-air contour charts for 300 and 200 mb., the location of the axis of jet streams of 80 kt. or more has been assessed once daily over the two years 1957–8. Results are presented for each of the four seasons by means of isopleths of frequency (Fig. 1) and also by means of frequency-roses in areas of 5 degrees of latitude by 10 degrees of longitude (Figs. 2–5); each rose shows the number of occasions of direction of the axis from the eight compass points. The area covered extends from latitude 30° N. to 70° N., and from longitude 60° W. to 30° E. An Appendix contains some discussion of the technique of locating the axis of jet streams on contour charts.

The characteristics of jet streams were described in a paper by Chambers in this Journal for July/October 1959. The present paper goes a stage further by giving the number of occurrences of jet streams per season over a two-year period in an area from the North Atlantic to the Mediterranean. The number of occurrences depends very much on the chosen definition, about which there is no general agreement. Whilst a jet stream may be fairly described as a fast-moving stream of air in the upper troposphere with great extension in the direction of the wind and persistence of the order of days, for statistical purposes it is necessary to be more precise. In this paper a critical speed of 80 kt. is required at the 300- or 200-mb. level in order that the stream shall qualify as a jet stream. Further discussion of this point is given in the Appendix, but any definition is largely subjective and it does not matter a great deal what definition is used provided the reader is aware of the limits to which the statistics refer.
Navigation and Communication in Project Beacon
Authors: Giesecke H.
Published: January 2010

This paper, and the papers by Gérardin and Payne which follow, were presented at the meeting of the Deutsche Gesellschaft für Ortung und Navigation held in Dusseldorf 5–7 June 1962 and are printed with that body's kind permission. An account of the meeting was published in the last number of the Journal (16, 111).

The scientific engineering review of the U.S. Task Force on air traffic control, known as Project Beacon, was completed in the fall of 1961. In their report to the Administrator of the Federal Aviation Agency, the Task Force makes no claim for originality of most of the ideas and recommendations which were presented. Consequently, many of the problems resulting from the proposed plan of action have been previously discussed. However, the very positive and specific treatment of basic principles and the presentation of clear decisions produced considerable impact. The blurred picture created by less definitive approaches has been brought into better focus. The remaining problems are reduced in number, implementation efforts can be concentrated and the probability of success has been increased.
Telecommunications and Identification of Radar Information
Authors: Gérardin L.
Published: January 2010

At the present time, radar is taking a more and more important part in air traffic control. That part is certainly going to develop even further in coming years, with the steady increase of traffic and the general use of jets on main airlines. Radar control has the advantage of presenting the controller with a clear picture of the position of each target, associated with an instantaneous view of the whole air situation. And, because radar information is renewed several times per minute, the situation displayed is always up-to-date. Unfortunately, that situation is rather anonymous. To make it usable, the targets observed have to be identified. In the first place, we have information about them from the flight plans; the identification of a particular aircraft then reduces to a choice between a few possible echoes only. A commonly used method is to send an order to the target to manoeuvre: the target obeying that order identifies itself by doing so. This method is simple, but not very quick. Moreover, the ordinary PPI unfortunately does not retain a memory of such an identification.
An Experimental Airborne Computer
Authors: Payne W. R.
Published: January 2010

The continual increase in the complexity and performance of modern aircraft give rise to the need for improved accuracy and versatility in the electronic aids available to the crew. The system described is an example of digital computing techniques applied to the problems of air navigation. Navigation was chosen as a typical problem but the flexibility of the computer would allow it to be applied to other in-flight problems, such as the calculation of fuel and air data.

Dexan (Digital Experimental Airborne Navigator) is the outcome of some three years' work at the Applied Electronics Laboratories of the General Electric Company at Stanmore and the Royal Aircraft Establishment, Farnborough. The calculations performed by the computer to carry out a particular navigation process are shown schematically in Fig. 1.
Hovercraft and the Collision Regulations
Authors: Clissold P. C. H.
Published: January 2010

In the discussion which followed the papers on Hovercraft Navigation, Captain M. J. Edwards raised an important point. ‘If the hovercraft is the stand-on vessel, it may be impossible for a large slow-moving vessel to take avoiding action in the short period between sighting and collision.’ This implied that both were following the International Collision Regulations, and these cannot be altered (except by local authorities in ‘inland waters’) without international agreement and the attendant delay.
A Theoretical Note on System Malfunctioning
Authors: Parker J. B.
Published: January 2010

The problem of estimating equipment serviceability when the apparatus consistsof a large number of individual components (possibly with standby features) islikely to be of increased interest now that navigational thought is being concentratedquite as much on the design of instruments the navigator uses as on theproblems of finding position at sea or in the air. The resulting exercise in combiningprobabilities of component failure is a fairly straightforward one but inview of the accelerating interest in the matter (see, for example, Cluley's articlein this Journal, 15, 387) a brief systematic treatment might be of interest toworkers in these fields.
The use of the Planetarium in Navigation Instruction
Authors: Wilkinson F. D.
Published: January 2010

The planetarium consists of an optical projector centrally situated under a dome. The viewers sit around the projector instrument in chairs designed to give a comfortable view over the whole interior. The instrument used by the writer is the Spitz A2, manufactured by Spitz Laboratories, Inc., Delaware, U.S.A. Seating is provided for 40 persons under a 20-ft. dome in the particular installation at the South African Nautical College General Botha, Gordon's Bay, Cape.
Interpretation and Behaviour in using Radar at Sea
Authors: Wylie F. J.
Published: January 2010

These two notes are the first of a series which will suggest to mariners the causes of collision at sea when radar is in use, by showing against each apparent cause an accumulation of court evidence and judgment, by isolating certain kinds of action which seem to have led to collision but have not been so regarded in every judgment and by examining certain judgments against a technically informed background.

In the articles which follow, a particular judgment is examined in the light of a more precise study of true motion as a direct source of intelligence at slow speeds, of plotting when courses and speeds are changing and of the suggestion that the Crossing Rules may be applied in fog after ‘ascertainment’.
Testing a Modern Gyro-Magnetic Compass
Authors: Ackerman J. D.
Published: January 2010

Gyro magnetic compasses are subject to a large number of errors, some of which may be eliminated, or at least greatly reduced, by careful design on the part of the instrument manufacturer and an intelligent operating drill on the part of the user. Table I shows errors under five basic headings, and allots to each error a symbol classifying it as:

(a) The responsibility of the instrument manufacturer (I)

(b) The responsibility of the aircraft manufacturer or its operator (A)

(c) Inadequate knowledge of the geomagnetic structure of the Earth's field (K)

Some sources of error in Table I are marked with an asterisk. It is these which the designers of the compass system described have endeavoured to eliminate.
II—The Operational Problem
Authors: Lamb P. M.
Published: January 2010

1. Introduction. By definition a hovercraft or air-cushion vehicle is a vehicle capable of being operated so that its weight is partly or wholly supported by a self-generated cushion of air that is dependent for its effectiveness on the proximity of the surface over which the vehicle operates. Thus from the safety aspect of navigation a hovercraft must be treated as a surface vehicle or craft; for any collision risks involved are proportional to the amount of conventional surface vehicles or craft and static obstructions, in the area of operation. The clearance of minor obstacles less than the hoverheight is practicable; but on present experimental craft with an undersurface clearance of three feet, these clearances are limited to small buoys, waterlogged obstructions and rock outcrops of limited height.
III—The Rhyl–Hoylake Experiment
Authors: Colquhoun L. R.
Published: January 2010

This paper has been written with the SRN-2 and VA-3 type of craft in mind; they are basically over water craft but with a capability of operating over land for the purpose of embarking or disembarking passengers and freight or of crossing mud flats or sandbanks. Immersed sidewall craft have not been considered since their problems are similar to those of high-speed launches. Overland air-cushion vehicles will, as Mr. Lamb has pointed out, most likely operate over prepared routes and therefore navigation should not present any problems.

The main advantage offered by air-cushion craft is speed. The second advantage is its amphibious capability. Because of this an air-cushion craft can operate routes that are out of the question for any other kind of vehicle except perhaps a helicopter. An example of such a route is the proposed Rhyl–Hoylake ferry, which at low water is almost an overland route.
IV—Communications and Navigational Aids
Authors: Morgan M.
Published: January 2010

The hovercraft will be required to move over land and water and, dependent on siting and the state of the tide, will also move over mixed conditions—land, mud, water, rocks, &c. It is a flexible vehicle and it will be capable of working in many parts of the world, and thought should be given right from the start of development to the use of aids to navigation which are self-contained.

The various weather conditions it will be expected to operate in and to maintain scheduled movement will vary from daylight—fine weather and clear visibility—to night and bad weather.
V—Radio Navigational Equipment for Hovercraft
Authors: Beattie J. H. , Dennis J. N.
Published: January 2010

1. Navigational equipment. The radio navigational equipment likely to be carried in a hovercraft will depend on the type of craft, the route or area of operation, and the economics of operation.

At present the operational requirements for navigational equipment are not fully crystallized because no hovercraft is yet in commercial operation and the operational requirements may well differ from trial requirements. However, two distinct types of hovercraft could become operational soon, the immersed sidewall hovercraft and the amphibious air curtain hovercraft.
VI—Hovercraft and the Collision Regulations
Authors: Hardwick J. H.
Published: January 2010

The preceding papers have shown that the present generation of hovercraft being used mainly on overwater routes should be considered as ships. The problems of operating these very fast craft in the same media as conventional vessels is receiving a lot of thought at the present time and perhaps a few more words on this subject would not be amiss.

In framing operational rules for hovercraft it has been proposed that they obey the Regulations for Preventing Collision at Sea in so far as their size and construction will permit. This is in fact the point of view which has been put forward by the Hovercraft Operational Requirements Panel, representing Hovercraft Developments Ltd. and the industry, in their provisional British Air-Cushion Vehicle Operational Rules.

If this approach is accepted, three questions immediately spring to the mind of the mariner;

(1) How manœuvrable are these machines that skid around on a cushion of air? The present papers have shown very clearly how well the turning circles and stopping distances of hovercraft compare with conventional ships. Control systems have improved tremendously since the first generation of machines and they are now far more manœuvrable than ships proceeding at a fraction of their speed. Experience in driving these craft has shown that this problem causes, little trouble, and as a result of various hovercraft demonstrations their manœuvrability at speed now seems to be generally accepted as satisfactory.
A Marine Radar System Incorporating Automatic Plotting
Authors: Beattie J. H.
Published: January 2010

The possibility of completely automatizing the navigation of merchant ships has been the subject of a recent study and prototype anti-collision radar equipment has already been engineered and evaluated. Indications are that, particularly from an economic point of view, there is little likelihood of such equipment going to sea in the foreseeable future, if it is accepted that a principle aim of any such system should be to reduce manning requirements below three watch-keeping deck officers and a captain. The main reason is that complex navigational problems exist at the beginning and end of the voyage and the presence of a trained watch-keeping deck officer offers the most economic solution to these problems. Detailed analysis of these navigational problems shows that the simple application of automatization techniques to existing equipment offers improved, standards of navigational efficiency and thus increased safety and higher productivity. A new radar plotting system, the Decca 969/ARP, is designed to assist a single watch-keeping deck officer to navigate more efficiently by automatizing certain difficult navigational tasks now performed manually.

That the economic need for automatic or semi-automatic navigational equipment and the design of such equipment is a relatively complex matter is illustrated by the recent very full report issued by the U.S. Maritime Administration. It was clear by 1958 that new navigational radar equipment would be required; a design study was therefore commenced.
Use of a Doppler Navigation System and Fixes to Monitor Aircraft Heading
Authors: Grocott D. F. H.
Published: January 2010

When trials of civil aircraft doppler navigation systems are carried out over land the pattern of results generally show a small along-track error component and a large across-track error component, whereas when the basic doppler radar is assessed, the errors over land are about ±0·2 per cent of distance gone and ±0°.2 in drift (standard deviation). It is not possible to quote system errors for all permutations of doppler equipments and compass systems but it is suggested that a good working figure for the across-track system error component would be about ±3 per cent (standard deviation), i.e. a compass error of ±1°.7. Advantage can be taken of the inherent accuracy of the doppler radar equipment to determine the heading error from a knowledge of track made good and the mean doppler drift along that track.

The standard twin-channel civil doppler navigation computer combines aircraft heading with doppler drift and doppler distance gone to form a ‘computer track’ in coordinates of distance along and across a preset track and distance. The computer is, in effect, meaning the doppler drift between selected points and adding this value to an arbitrary datum (aircraft compass) to form the computer track. If we can determine the true track over the ground we can assume that the error between computer track and actual track is caused entirely by error in the arbitrary datum, i.e. heading error.
Sundials for Navigators
Authors: Bini Mario
Published: January 2010

Having some time ago been requested to design a sundial for the Hydrographic Institute of Genoa (Fig. 1) I went through various books and found that the methods indicated for drawing sundials were all based on graphical constructions. Although quite interesting these methods have the inconvenience of all graphical solutions, that they require constructions which, besides being complicated, turn out to be rather inaccurate, especially when lines cross at small angles, as inevitably happens outside a limited central area of the drawing. To avoid this I worked out a numerical system, related to the familiar methods of astro-navigation, which, by means of simple formulae, gives the coordinates of the points necessary to design a sundial. As the bibliography I examined is, of course, limited, I am not in a position to state whether this method of calculation is new or not; I describe it here hoping it may interest people who have sometimes wondered how sundials are made.
Calculating the Sun's Position for Calibration of Radar Antennas
Authors: Blicq R. S.
Published: January 2010

Recently I was asked to assist the engineers in my company (a Canadian electronics firm) devise a method for using radiation from the Sun to check the alignment of heavy ground radar sets to within very fine tolerances. The degree of accuracy would have to be better than five minutes of arc in azimuth for search antennas, and three minutes of arc in elevation angle for height finding antennas. Solar radiation in the microwave region of the radio frequency spectrum would be used as a reference. The antenna reflector would be rotated in azimuth and elevation until maximum solar radiation was reflected into the waveguide horn and thence to the radar receiver. The moment peak detector current was obtained, the antenna would be locked in position and the exact G.M.T. noted. Normal astro-navigation calculation methods and tables would then be used to calculate the Sun's true azimuth and elevation angle, which would be compared with that measured by the antenna to determine its accuracy.

Since none of the engineers had previous navigation experience, they had run into difficulties when they tried to devise a method for calculating the Sun's position to within the requisite accuracy limits.

The first difficulty was the fact that most antenna calibrations would be performed by field technicians having no knowledge of astro-navigation tables and calculation methods. They would be at extremely remote radar stations across Canada and thus would not have an opportunity to ask questions if our instructions proved ambiguous.
Collision Regulations
Authors: Neumark O. W.
Published: January 2010

Over a decade ago there was some controversy about the selection of an international standard airfield approach lighting system. At a very late stage, the R.A.E. produced a visual simulator of great simplicity on which any administrator could fly approaches using any of the rival systems. His performance could be checked but, what is far more important, he obtained personal and realistic visual experience. If this simulator had been available in 1945 it might have saved many millions spent on the flight evaluations of the rival systems and years of international conferences.

In the present controversy on collision avoidance regulations in the air and at sea, time and wealth could be saved by the creation of a visual and dynamic simulator in which all persons attending symposiums on collision problems could obtain synthetic visual experience of the present day avoidance regulations and of the new conventions proposed by E. S. Calvert and S. H. Hollingdale.

Curiously enough, such a simulator would not be very costly. It would consist of a very large hangar and a number of small electric two-seater cars somewhat similar to those known as ‘Dodgems’ often seen at Funfairs.

It would be used quite effectively for simulating air traffic as a high percentage of all near-misses occur in the horizontal plane but it would be desirable to gimbal the cars so that they can bank when turning.

Simulation of nocturnal traffic requires only black-out and navigation lights.
I—The Inertial Reference Platform in Civil Aviation
Authors: Stratton A.
Published: January 2010

The objects of this paper are to present in perspective the range of application of inertial techniques that are available for civil use and to suggest how the information that can be obtained by this means relates to that from other airborne sources.
III—Inertial Platforms for Flight Control and Navigation
Authors: Collinson R. P. G.
Published: January 2010

In the next decade there will be an increasing demand for more accurate self-contained navigation systems due to more stringent air traffic control requirements, particularly with the introduction of the supersonic transport. Although inertial systems have been fairly widely used in military aircraft and missiles, the only self-contained systems in service in civil aircraft are dead reckoning systems based on measuring the aircraft's velocity and heading and drift angle. A big improvement has been effected in the measurement of velocity and drift angle by the introduction of doppler radar. The accuracy achievable with doppler is not matched by the accuracy of existing heading reference systems and the overall accuracy is, at present, inadequate for future requirements.

An inertial navigation system is a possible alternative but its cost will be two to three times that of a doppler heading reference system.
IV—Some Practical Aspects of the Problem
Authors: Sullings F. J.
Published: January 2010

This paper is concerned with the effect on airline operation of the introduction of inertial equipment, from the engineering viewpoint. It is difficult to avoid entirely all operational considerations but the main object here is to stress the economic and engineering aspects arising from the use of this equipment.
V—An Economic Perspective
Authors: Williams J. E. D.
Published: January 2010

During the first years of the last war the navigational problem was how to get to the target at all. In such conditions solutions to the navigation problem are priceless. Towards the end of the war it came to be accepted that, in transport operations at least, guidance to destination was almost a matter of course. Navigational performance ceased to be regarded as a question of success or failure and became a question of efficiency. This development in air transport we owed most of all to the radio compass.

As the volume of civil traffic grew, it rapidly became clear that the major limitation on navigational efficiency of air transportation was (and it still is) air traffic control. Although there has been considerable interest in the optimum trajectory particularly in connection with turbine aircraft, the development of refined operating techniques has been damped by restrictions on their application by A.T.C. The flat assertion by some would-be supersonic aircraft manufacturers that the supersonic (unlike the subsonic) jet will not take NO for an answer from A.T.C. once it is committed to a flight programme has recently been a most valuable stimulus.

The A.T.C. problem is well known. It is generally accepted that the capacity of an air space depends on the quality of navigational data, of the data link between aircraft and control centre and of the data correlation capabilities of the centre.
Shore-based Pilotage
Authors: Oudet L.
Published: January 2010

A radar installation, designed to serve as a navigational aid, is in course of being set up at the mouth of the Gironde. It is one of a long series of port- or river-radars installed in similar conditions. So far, these have been entrusted to port officials. They are used, almost exclusively in reduced visibility, to give ships accurate information about their position, and in particular to keep them informed of the presence of ships in their vicinity. Their chief function, in association with radio-telephony, is to allow traffic to be controlled at times when visual signals cannot be distinguished.

The Gironde enterprise is more ambitious. The intention is to entrust the radar to pilots so that they may guide shipping, in both clear weather and fog, without having to go on board. This method is to be used between the sea and Le Verdon, and in particular at the bar, the trickiest section of this stretch. It should entail a considerable reduction in the cost of pilotage, the chief of several reasons for this being that there would no longer be any need for a pilot-vessel. It is worth examining whether this is a sensible plan and under what conditions it can be made effective, in the Gironde or elsewhere.

That a pilot should use radar to direct a ship from some distance away is a completely revolutionary idea.
The Neglected Sea
Authors: Brundrett Frederick
Published: January 2010

The following is an abbreviated version of the 29th Haldane Memorial Lecture given by Sir Frederick Brundrett in the University of London Senate House on 7 March 1963. Sir Frederick is Scientific Adviser to the Civil Service Commission.
Graphical Methods of Finding the Sun's Azimuth and Elevation
Authors: Shinn D. H.
Published: January 2010

Like Mr. R. S. Blicq (Journal 15,456) we have also been concerned in supplying details of the Sun's position to engineers on radar sites who use radiation from the Sun for, at present, two purposes:

(a) Measuring or checking the radiation pattern of the aerial in the vertical plane.

(b) Lining up the aerial in azimuth or elevation.

For these purposes the required accuracy of computation is usually about ±0°·1 in azimuth and elevation. Greater accuracy is never required, but less accuracy is sometimes adequate, up to ±1°.

We have found that graphical methods appeal most to engineers, and that even when a full table of values is supplied to them they prefer to display this information in graphical form. We have accordingly evolved a simple method of constructing graphs of elevation against time, and azimuth against time.

In order to achieve the required accuracy of ±0°·1 in elevation we have constructed a graticule of size 21 in. × 40 in. A skeleton version of this is shown in Fig. 1. The engineer has to know his latitude, and to find, from the Nautical Almanac or other source, the time of local noon (i.e. when the Sun is due south) and the mean declination, δ, of the Sun during the period of observation, which usually lasts up to three hours.
Surveying Deep-Draught Routes
Authors: Winstanley J. D.
Published: January 2010

Before the war it would have been comparatively easy for anyone interested to quote the names of all the really large ships afloat, if not some of their vital statistics. To do so today would require a considerable feat of memory as the number of vessels in the 50,000 ton and upwards class has reached almost 200 with, in recent years, a growing emphasis on those of over 100,000 tons. In the last few years no less than 51 of these monsters of over 100,000 tons have appeared at sea representing about 1/10th of the total world tonnage completed during that period. There are several 326,000 tonners ploughing the seas; 350–375,000 tonners are on the slips, with 750,000 tonners on the drawing boards and the possibility of topping the 1 million mark in the future.
Satellite Systems for Geophysical Exploration at Sea
Authors: Moody Alton B
Published: January 2010

Geophysical exploration involves the measurement, at the surface of the Earth, of physical quantities which will provide information about the structural configuration of the Earth's crust. Geophysical surveys are made for petroleum and mining companies to discover subsurface structures favourable to the accumulation of minerals of economic significance.

When geophysical exploration was extended to sea, pinpoint marine navigation became a requirement so that the prospector could return to the exact site of the geophysical anomaly. At first, operations were so near the shore that position determination was no problem. Visual observations were quite adequate. As operations pushed farther from land, high-accuracy electronic systems were pressed into service. Such names as Decca, Lorac, Raydist, and Shoran are familiar in the oil industry. But when operations extended beyond the range of precision radio systems and into areas where they were neither available nor could readily be made available because of hostile terrain, natives, or politicians, or where adequate surveys of shore transmitting stations were impractical, other means of navigation were needed. Navigation satellites, used in conjunction with other navigation equipment, fulfil this need.
Satellites for Offshore Exploration
Authors: Maybourn R.
Published: January 2010

While the position fixing techniques employed in offshore drilling and exploration are in many ways similar to those used by the shipping industry—and, indeed, many systems are available to both—there are, nevertheless, several important differences. Accuracy and repeatability are two, in particular, which stand out. It is difficult to state in precise terms what accuracy is acceptable in an offshore survey because the customer is often obliged to accept the best of what he is offered but something of the order of 100 metres is likely to be the target. This is very much better than is required by the average ship out of sight of land or, for that matter, is obtainable in many cases with the instruments available. Repeatability means little to most navigators who rarely have any requirement to return exactly to any position denned in the past. The surveyor, on the other hand, has a continuing need to do this, running lines across his survey grid for check purposes, or at a later date when carrying out another survey or positioning a drilling rig.
Position Experiments Using Distance Measurements of Satellite ATS—3
Authors: Goebel W. , Schrick K. W.
Published: January 2010

Following an invitation by N.A.S.A., the Bundesrepublik Deutschland carried out an experiment with the U.S. satellite ATS-3 (Applications Technology Satellite). The satellite is synchronous, or stationary with respect to the Earth's surface, at an altitude of about 35,800 km. above the equator.

The object of the experiment was to determine the system parameters for a navigation satellite system. This included investigation of the bandwidth of the ultra short-wave band used, and testing speech and data transmission between ships and the mainland, as well as carrying out determinations of baselines. The results are published in Research Report FB69—37 of the Bundesministerium für Bildung und Wissenschaft. The experiments were carried out during two expeditions of the German research ship Meteor, under the direction of the Deutsche Hydrographische Institut. The expeditions were to the west African coast in the spring of 1968, and in the summer to the Faroe Islands. In the fall of 1968 investigations were completed by measurements from a mainland station which was installed on the institute building of the Deutsche Forschungs- und Versuchsanstalt. This paper describes only the position experiment.
Some Aspects of the Solution of the Main Problem of Inertial Navigation
Authors: Ishlinsky A. Yu , Klimov D. M.
Published: January 2010

The problem of the autonomous determination of the position of a moving object (inertial navigation) on the Earth is solved by gyros, accelerometers, integrators and a computer. We will indicate three possible schemes of inertial navigation.
Distance Off by Vertical Sextant Angle
Authors: Black A. N.
Published: January 2010

The note by J. W. Crosbie prompts the writer to the following comments. Lecky's Tables2 do not cover vertical angles below the geometrical horizon (zenith distance =90°), or, indeed, angles of less than 10’ above it. Crosbie's method, also, does not cater for angles below the geometrical horizon, though it could be adapted to do so. His extraordinary evolutions with the traverse tables, undertaken to avoid solving a quadratic equation by orthodox methods, are fascinating. Surely, a slide rule, with which the equation could be solved in a few seconds, is available in today's chartroom.
Rhumb-line Sailing
Authors: Williams J. E. D.
Published: January 2010

If Turner is right that ‘the underlying theory of the traditional approach (to rhumb-line sailing) is obscure’ and that there is a ‘lack of ready availability of a table of distances of parallels of latitude from the equator, it is certainly not the fault of this Journal which precisely 20 years earlier published a paper which gave:

1. The correct mathematical theory of rhumb-line sailing on an oblate spheroid.

2. The name ‘meridional distance’ to what Turner now calls the L(φ) function.

3. A table to reduce latitude to meridional distance.

4. A rule of thumb procedure to calculate rhumb-line distances correctly with no more labour than that which has always been used to do it wrongly.

5. A method (with table) for use on the spheroid when the track angle is nearly 90° and the method Turner discusses is impracticable.

6. A survey of methods and tables then current.
Visual Judgments in Motion
Authors: Calvert E. S.
Published: January 2010

Introduction. The judgments discussed in this paper are mainly those which the pilot of an aircraft has to make in order to land. Some of these, as, for instance, the judgment of alignment, are similar to those made by the driver of a moving surface vehicle, but some, as, for instance, the judgment of approach slope, are peculiar to the pilot, and are very much more difficult. The main difficulties of the pilot arise, however, from the fact that an aircraft has six degrees of freedom and is controllable about all three axes, whereas the surface vehicle has only three degrees of freedom and is controllable only about the vertical axis. In bad visibility these extra freedoms confuse the visual indications in ways of which the person who has only driven a surface vehicle has no conception. The result of this has been that until recently most of the engineers concerned in the layout of airports have not realized that pilots have special difficulties; while the pilots, not having studied visual psychology and perspective, have been unable to analyse these difficulties, or even explain them in terms intelligible to the engineers. In this country, we have been able to find methods of bridging the gap, and enabling both parties to talk the same language. The practical result of this can be seen at London Airport.
The National Institute of Oceanography
Authors: Deacon G. E. R.
Published: January 2010

History. The foundation of a ‘British Oceanographical Institute’ was first proposed, at a meeting of the Scientific Advisory Committee of the War Cabinet in 1944, by Vice-Admiral Sir John Edgell, K.B.E., C.B., F.R.S., then Hydrographer of the Navy, who expressed the view that Great Britain, in its contribution to research in oceanography, had fallen behind other countries, including many with no comparable traditions of interest in the oceans of the world and their navigation. The Scientific Advisory Committee accordingly suggested to the Royal Society that its National Committee for Geodesy and Geophysics should be invited to discuss, through its Oceanography Sub-committee, the general question of the need for and the appropriate constitution of a National Institute of Oceanography, and to present recommendations for the consideration of the Society and eventually of the Government.

The report of the Sub-committee for Oceanography, which was accepted by the Royal Society and referred to the Scientific Advisory Committee, was strongly in favour of the setting up of a National Oceanographical Institute in Great Britain with the purpose of advancing the science of physical oceanography in all its aspects. The Scientific Advisory Committee supported the proposals in the report, but considered that the work of the Institute should embrace both physical and biological oceanography.
The London–Capetown Record Flights of 1953
Authors: Bower Squadron Leader D.
Published: January 2010

In December 1953, a Canberra of the Royal Air Force Flying College was christened Aries IV, and thus became the first jet aircraft to bear this name, long associated with navigation development flights. This paper describes the first operational mission of Aries IV, an attempt on the F.A.I, point-to-point record for the London–Capetown route, in both directions.

The flight was originally planned as a final long-range exercise for students of the College, but since a great deal of practice had already been gained in maximum range cruise techniques it was decided instead to concentrate on the more complex problem of covering the distance in the minimum time. To add incentive, permission was sought and granted for the flight to be officially timed by Royal Aero Club observers.

Two crews were chosen, one for the outward and one for the homeward legs, each consisting of one pilot and two navigators. A two-man navigation team is rather lavish for ordinary route flying, but was adopted in this case to give experience to as many students as possible; in addition it resulted in faster astro work and more continuous map-reading, and gave a foretaste of the working conditions to be expected on arctic flights where a two-man team is thought to be necessary.
Sandwaves in the Southern North Sea and in the Persian Gulf
Authors: Cloet R. L.
Published: January 2010

In 1935, Van Veen, Chief Engineer of the Dutch Waterstaat, wrote about some giant sandwaves which he had recorded on the Varne Bank and the Falls in the Straits of Dover. They were up to 40 feet high from trough to crest, and were found at either end of the banks. Although these dimensions seemed somewhat unusual at the time, such waves had been known to exist since the end of the last century, when Osborne Reynolds, experimenting in a model tank, discovered in 1899 that tidal streams could produce what he called ‘very large current ripples, possibly 7 or 8 feet high and 80 to 100 feet apart.’ In 1901, Vaughan Cornish described having seen giant ripples of that order in several localities, among them the North Goodwin Sands.

Giant waves are by no means rare. Early in 1953, H.M.S. Challenger obtained a trace on the Cross Sands, east of Lowestoft, on which several waves between 25 and 30 feet high were recorded in about 20 fathoms of water. During the summer of 1953, one of H.M. survey vessels recorded waves up to 50 feet high in a depth of water above the crests of about 12 fathoms on a sandbank north of Perim Island in the Red Sea.
Plotting Sights with the Douglas Protractor
Authors: Humphreys F. K.
Published: January 2010

The 10-in Douglas protractor can be modified to reduce the time taken to plot astronomical sights in the following manner. Two narrow slots are cut parallel to the central E.–W. line, and ¾ in each side of it, from the central N.-S. line to the western margin of the graticule.