bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Automation of Ships' Navigation Systems
Authors: Clayton C. T. , Kurz Charles G. 
Published: January 2010

The United States Maritime Administration recently published the results of a study, undertaken by the Norden Division of the United Aircraft Corporation, on automation and the operation of merchant ships. Mr. Clayton, the author of this important report, described the findings of this investigation, in so far as they affect navigation, to an Institute Meeting held in London on 16 November 1962. The paper, which is presented here, was written in association with Mr. Kurz of the U.S. Maritime Administration. It describes navigation systems for partially and fully automated vessels, and discusses the basic system requirements, accuracy and reliability criteria. A command philosophy for automated ships is developed, and finally a marine course computer, which is the first component of a partially automated navigating system already manufactured, is described. This is the first of several equipments being manufactured under contract to the Maritime Administration.In early 1959 United Aircraft Corporation, led by its Norden Division as systems manager, undertook a company-sponsored study of the technical feasibility of operating merchant ships automatically. The results of this study were circulated throughout the industry. In April 1960 the Maritime Administration awarded a contract to Norden to study the economic and technical feasibility of automating merchant ships. The principal objective of the study was to develop a consistent series of planned, orderly, and reasonable steps towards completely automatic ship operation. The technical feasibility and economic advantage for each significant advance would be thoroughly established and then presented in a form suitable for selective application according to the particular requirements of individual ship operators.
The Navigation of a Communication Satellite
Authors: Clegg J. E. 
Published: January 2010

The navigational aspects of the requirements for a medium altitude satellite communication system are discussed. Twelve satellites have to be injected into a circular equatorial orbit with very great precision. It is not practicable to navigate the launching vehicle accurately enough to obtain the correct orbit at first injection and the satellite itself has to be controlled and adjusted until finally it is correctly positioned with the right period.The navigation of the third-stage rocket is discussed as this effects the limits of adjustment required for the satellite. Some error in period is necessary at injection in order to position the satellite correctly in orbit, in a reasonable time. A suitable tolerance on the period at injection is 3 minutes in 8 hours. This must be reduced, by fine adjustment of the satellite speed, to less than 30 milliseconds. Methods of measuring the orbital period to this accuracy are discussed.When the 12 satellites are finally in orbit and equally spaced around the orbit they should remain for up to 5 years with the pattern substantially undisturbed.This paper was presented at an Ordinary Meeting of the Institute held in London on 18 January.The basis of navigation is the finding of present position and velocity so that the necessary action can be taken to guide the craft or vehicle to its destination.
High-level turbulence over Europe and the Mediterranean
Authors: Briggs J. 
Published: January 2010

Aircrew reports of turbulence at heights between 20,000 and 40,000 ft. are analysed to show geographical and seasonal variation in incidence of turbulence. It is found that there is generally a summer minimum of turbulence and an autumn or winter maximum.Reports of the occurrence or non-occurrence of turbulence have been made for the flights of Comet 4B aircraft of British European Airways. Although the assessment of the turbulence was no more than subjective it was thought that the uniform nature of the aircraft, operating over a large number of flight sectors in the European and Mediterranean areas, and the fact that ‘nil’ returns were also made, could give useful indications of the geographical and seasonal variation of the incidence of the high-level turbulence. An analysis of the reports, made during a period of twelve months, is presented here.
Service Area Calibration of Hyperbolic Navigation Systems
Authors: Sullivan Joseph E. , Porter William A. 
Published: January 2010

It is well known that in low-frequency hyperbolic navigational systems the phase differences measured by the receiver do not correspond precisely to the hyperbolas on the plotting chart. This is largely because of variations in the terrain over which the waves are propagated. The system service area may be sampled so that the curve distortions can be ascertained at selected points. This article discusses how the whole service area can be calibrated, given a knowledge of the grid distortions at a sample of points. The mathematical treatment takes into account the correlation between the grid distortions at adjacent sampling points by using autocorrelation theory.The degree to which fixing accuracy is improved by the proposed method of calibration is assessed against the background of an actual set of field measurements.Mr. Sullivan is Head of the Applied Research Group of the Navigation and Guidance Laboratory at the Institute of Science and Technology. Dr. Porter is Assistant Professor of Electrical Engineering at The University of Michigan, and Head, Analytical Research Group of Navigation and Guidance Laboratory at the Institute of Science and Technology.In low-frequency ground-wave navigation systems such as Loran-C and Decca, position information is determined from measurements of time and/or phase differences in signals received from several separately located transmitter stations. A pair of stations generates a family of hyperbolic lines which are the loci of points of constant time/phase difference. Two station pairs provide a grid of hyperbolas. By measurement of the time/phase difference between the signals from two transmitters, the receiver is located on a hyperbolic line. The same receiver is located on a second line by similar measurement which uses another pair of stations; the receiver is thus fixed specifically at the intersection of the two lines.
Radar Simulator Courses
Authors: Burger W. , Corbet A. G. 
Published: January 2010

Some lessons and observations experienced during a series of radar simulator courses in the period of one year are listed below:1. The practice of plotting is generally favoured by the students and they learn quickly how to determine which targets are of concern and should be plotted and which targets may be rejected. It has to be pointed out fairly often that recordings should be taken down in an orderly manner and that—besides the time, bearing and range of a target—the heading and speed (or log reading) of the observing vessel should be written down with each set of observations.
Recommended Routes for Ships in Congested Waters
Authors: García-Frías J. 
Published: January 2010

Captain A. F. Dickson's paper entitled ‘Recommended Routes for Ships in Congested Waters’ (Journal, 17, 217) suggests the introduction of a principle which I advocated in two previous papers, the second of which was presented at the Conferenza Intemazionale Sulla Disciplina dell ’uso del Radar, in Genoa, May 1957. Captain Dickson writes in his article:It is therefore suggested that the measures to be taken should involve the application of one simple basic rule, that in all cases ships should keep to the starboard side of any channel and that traffic rounding a headland should be separated so that ships proceeding in opposite directions will have a port-to-port passing. In addition, wherever possible the different streams of traffic should be separated by a lane which would be a virtual no-man's-land between ships sailing in opposite directions. The lane might well be shown in colour and British Admiralty experience seems to indicate that purple is a good colour for chart usage, so the lane might be known as the “purple lane”.In my works it was stated ‘Coastal radar navigation constitutes a very valuable means of making feasible an ordering of the natural traffic streams by regulating them according to the requirements of each area, following experience.
Bridge Lighting
Authors: Roberts C. J. 
Published: January 2010

The fundamental necessities of efficient bridge and chartroom lighting, which matter appears to have been ignored even on many of the latest vessels, are the provision of:1. Adequate illumination of all instruments in a uniform manner.2. Efficient illumination of the chart.3. A reduction of the high contrast of light values between chartroom and wheelhouse and the elimination of the sources of glare.These three essentials can be combined to render the overall illumination of the navigating bridge efficient and practical, whether the ship has a separate chartroom and wheelhouse or the more modern chartroom and wheelhouse combined.All bridge instruments, such as clocks, compasses, telegraphs and the numerous indicators, should be made to a uniform specification—all with ‘back’ or ‘edge’ illumination provided by red lamps. Where practicable these instruments should have black dials with white lettering. An extra refinement is to have the lettering painted with a luminous paint. Illuminating the instruments in this manner would also afford a certain amount of illumination to the otherwise dark navigating position. This would in turn tend to alleviate the high contrast of light between the chart area, which of necessity must be lit, and the total darkness outside.
I—The Control Characteristics of Hovercraft
Authors: Pennington W. A. 
Published: January 2010

Any discussion on the navigational problems of hovercraft must obviously be closely associated with the control characteristics of the craft. Although these machines have been widely publicized as capable of operating over almost any terrain which is reasonably flat, it will be assumed that the present discussion is concerned primarily with operation over water.The word hovercraft may be regarded as a generic term in the same category as aircraft, ship, motor vehicle &c., and practical examples are likely to take a variety of forms depending upon their particular application. Thus, the control characteristics and the way in which they affect the navigational problem are likely to vary, in degree at least, amongst the different types. Again, it must be realized that the hovercraft as a transport system is only at the beginning of a long development phase, and any remarks of a general nature which are made at this time must be read in that context. Even at this early stage, however, two distinct applications of the hovercraft principle, as applied to over-water transport machines, have emerged and it is important to appreciate the difference between them.
The Design of Reliable Digital Computers for Air Traffic Control
Authors: Cluley J. C. 
Published: January 2010

A number of air traffic control authorities are now introducing electronic digital computers into air traffic control systems in order to speed operations and reduce the burden on controllers. These machines will initially be used for the routine clerical and data storage operations, but their full capabilities can only be used if they are given a much greater share of the control task and allowed to make logical decisions and intervene in the handling of the traffic. In such cases the computer will be performing a task that cannot be handed over to a human operator at a moment's notice in the event of a machine failure, and extreme reliability becomes probably the most important single attribute of a computer used in such a system.Although computers of adequate speed and capacity are being produced for commercial and scientific uses, with reliabilities sufficient for these purposes, the frequency of faults and the time required for routine maintenance are both far too large to permit their full-time use in an air traffic control system. The reliabilities of typical components and systems are discussed in the following section.1. The reliability of typical components and systems. The reports of a number of computer users suggest that ‘availabilities’ of 97–99 percent are readily attained, so that only 1–3 percent of the available working time is lost due to unscheduled maintenance.
The Principles Underlying the Collision Regulations
Authors: Oudet L. 
Published: January 2010

A great deal has been written, especially in the last few years, on the subject of collision at sea. The increase, however, in the speed of ships and in the density of traffic so magnifies the complexity of the problem that even closer and more earnest study is still called for. Three fields of inquiry demand our attention: technical advances, procedure, and the human factor. Of these, the widest and most promising might seem to be the first. Its importance is undeniable, and I am by no means the only one to have pointed out that with the new difficulties it raises it supplies also the appropriate solution. Even wider, however, and more complex is the field of human study; this covers both the others, for in this the final objective is to enable men to master what they have won for themselves, and this they cannot do—here we meet the familiar problems of philosophy, ethics and religion—unless they first learn to master themselves.Compared with these two fields, the technical and the human, that of procedure must at first seem quite insignificant. Can one seriously imagine that there is in fact some new method of avoiding collisions, so abstruse that no one has yet been able to discover it? In my small book on the use of radar I wrote: ‘The Regulations envisage two ways of avoiding collision:1. A movement carried out in concert with the other vessel.2. A reduction of speed, if necessary to zero.
I—by P. L. Stride
Authors: Stride P. L. 
Published: January 2010

Airborne weather radar equipment, carried for detection of meteorological phenomena, is now well established as a standard equipment for most transport aircraft, and is even being specified for the larger executive types. It may be useful, therefore, to review the basic factors which influence the value of the information obtained and the progress made with equipment designs during the last decade.Turbulence on its own cannot be detected by radar. The radar defines areas in which some form of precipitation is occurring, i.e. heavy rain, hail, ice crystals or snow. Of these, the areas in which large water droplets fall as heavy rain on the ground or exist in suspension in the cloud are of most interest, since they are inevitably associated with convective cloud formations. All other information relating to the possibility of turbulence, ice formations, hail, &c., must be deduced by the observer from his knowledge of the mechanism of such meteorological phenomena. However, it is clear that the radar must display information on large droplet type clouds only. The presentation of small water droplet clouds not associated with convective processes would serve only to confuse the picture.The theory of reflections from meteorological phenomena is dealt with very thoroughly in the literature and here only the main conclusions will be summarized to show how the characteristics of a radar set affect the information produced.
True Motion in Relative Displays
Authors: Milwright A. L. P. 
Published: January 2010

The system proposed by Manley (15, 172), to produce true motion on relative displays seems to suffer from two serious disadvantages which were not referred to. The first is that there would be a serious degradation in the resolution of the stored picture, since every time an original echo is rewritten into one of the Tenicon storage tubes the echo size would be increased both in range and bearing by the size of the beam spot. No doubt the full effect of this increase could be reduced by the introduction of pulse shaping circuits between the read-out and write-in points, but nevertheless the original small echo would be considerably increased in size if a number of read-out write-in operations were carried out as would be the case if the information was stored for a sufficiently long time to show true track. As an example, without applying any special pulse shaping techniques a small echo, two spot diameters long and one spot diameter wide, would be increased in size by 65 spot diameters if stored for 30 seconds (i.e. 10 scans of the aerial) and would be increased by 1890 spot diameters if stored for 3 minutes.The second disadvantage is probably the more serious. Since any signal entering the system remains there until the stored information is cancelled, the effect of interference would be to flood the screen completely in a short space of time.
The Gestation and Birth of my Nautical Tables
Authors: Burton S. M. 
Published: January 2010

The imaginary question I propose to answer in this address is—how does it come about that a person with such a very ordinary sort of intellect, and certainly with no particular flair for mathematics, should be the author, or nominal author, of such an imposing publication as a volume of nautical tables?To build up the background to the story briefly let me explain that in my training ship days I received the impression that a ship's position was found by mathematical calculations. True, we knew that sextants and chronometers were necessary instruments in the scheme of things; but they only seemed to supply certain ingredients to the calculations that ultimately produced one of the components, latitude or longitude. It was when I was consigned to a stretch of service on the North Pacific in 1927 that, for something to do, I decided to try and improve my limited understanding of astronomical navigation. In the volume of Raper's Tables which I had always used there was an appendix by the Naval Instructor William Hall which explained what was then called by the Navy ‘The New Navigation’, and gave four-figure cosine-versine tables for the work. It was in reading, and re-reading, and thinking about Hall's marvellously lucid explanation of the St. Hilaire process that the light suddenly burst upon me.
II—The Azimuth Alignment
Authors: Whalley R. 
Published: January 2010

Inertial navigation systems have become of great importance in the navigation of military aircraft and in recent years there has been a growing interest in their application to civil transports. A special problem arises with this class of equipment in that the axes require to be set before navigating and a particular difficulty arises with the azimuth. This involves penalties in special pre-flight routines or in extra cost and complexity of equipment which are of concern to the airline operator who is attempting to assess the usefulness of inertial techniques. The purpose of.this paper is to discuss the general principles on which azimuth alignment schemes can be based with reference to the likely penalties involved.The paper is primarily concerned with systems where aircraft accelerations are measured by accelerometers mounted on a gyro stabilized platform and then integrated to obtain velocity. The velocity may be either used directly in a navigation computer or mixed first with velocity from another source, such as doppler radar, as described in Ref. 1. However, all dead reckoning systems require a knowledge of heading and in cases where a better accuracy is required than can be obtained by reference to the Earth's magnetic field, a low-drift gyroscope can be used as an azimuth memory. Some of the alignment schemes discussed would be applicable to these heading references as well as to stable platforms with accelerometers. With most inertial systems, alignment to the Earth's magnetic field would be made before fine alignment commenced.
The Navigator's Horizon
Authors: Chaplin J. M. 
Published: January 2010

In his Presidential Address (Journal 16, 1) Dr. G. E. R. Deacon, C.B.E., F.R.S., says: ‘We have learnt from the Journal that one of the most frequent sources of error is a poor horizon, and recent (my italics) experiments by our American colleagues have shown that much can be gained by fitting a more powerful telescope in the sextant so that stars can be used while the horizon is better illuminated. They showed that it is better to look at the star directly and to make the horizon the reflected image.’Dr. Deacon has been misled. In the ‘old’ Discovery from 1925 onwards (and before that in various surveying ships, whilst on passage), in which I was Navigating Officer, the horizon was always brought up to the star. A ‘sounding’ sextant also was always used. This is lighter than an ordinary observing sextant and mine had a large, aluminium telescope, of much greater power than the star telescope of an ordinary sextant, and with a very large object glass.It was, however, graduated only to minutes of arc. To overcome this the altitude was pre-set for every contact to fixed intervals of, I think, 5′; this had the additional advantage that if the time of the middle contact agreed with the mean of the others it formed an excellent check on the accuracy of the sights and could be seen at a glance.
Manœuvre Demand Control for Aircraft
Authors: Shanks G. T. 
Published: January 2010

The coverage of this paper, which was presented at an Ordinary Meeting of the Institute held in London on 18 March 1970, includes:(1) A brief review of current aircraft flight control systems.(2) A discussion of the benefits to be gained in terms of manual handling and full automatic pilot modes, in using feedback control techniques in the primary flight controls (Manœuvre Demand Control).(3) A description of the work done on Manœuvre Demand Control at the Royal Aircraft Establishment, Farnborough, in the Avro 707C aircraft and in the Hunter Mk. 12 aircraft.
Kau Moala the Tongan Navigator
Authors: Hilder Brett 
Published: January 2010

The whole question of Polynesian navigation is highly controversial. Dr. David Lewis's paper ‘Ara Moana: Stars of the Sea Road’, in the July issue of this journal, prompts me relate the story of Kau Moala in somewhat greater detail and to assess his achievements and motives, largely from his own account of his voyages.Kau Moala was a Tongan Chief renowned for his epic feat of navigation which probably took place in the years just before 1800. The details come to us from a young English castaway named William Mariner, who spent several years in Tonga and knew Kau Moala personally. When Mariner got back to England his experiences were compiled by J. Martin and published by John Murray, London, in 1817. The work is generally known as ‘Mariner's Tonga’, the full title being An Account of the Natives of the Tonga Islands. The story of Kau Moala's famous Odyssey is given on pages 307–322 of volume I of the second edition, published in 1818. Mariner gives the Chief's name as Cow Mooaly.The story starts with Kau Moala going from Tonga to Fiji to engage in some warlike adventures to enhance his prestige, as many another Tongan Chief had done before, and as several did later. After two years of fun and mischief he decided to return home, and set out in his large double canoe.