Table Of ContentIET History of Technology Series 6
Technical History of the BT Technical History
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Beginnings of Radar inn
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Radar has become an essential factor in air and sea travel, has affected all areas of ois of Radar
military science and, most important of all perhaps, has considerably influenced the ft
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progress of electronic engineering. R
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This book is the first general history of radar to be published, and one which covers the ay
independent but more or less simultaneous emergence of radar in several countries in d
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the 1930s. a
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Some of the earliest proposals for the use of radio waves to detect objects at a distance r t
are first dealt with. The narrative ranges from the concepts of Nikola Tesler in 1900 and h
the experiments of Christian Hulsmeyer in 1904 right through, in chronological order, to e
the commercially sponsored experiments of the pre-war days. The historical events and
the military influences, which shaped the ultimate development of radar in each country,
are then considered.
The book also sets out to explain the basic principles of radar and, where applicable,
historical aspects of the evolution of these principles are dealt with. The study, while
S.S. Swords
underlining the significance of the cavity magnetron, purposely restricts itself to the cavity
magnetron era of radar.
Abundant references, which could facilitate further research, are given.
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The Institution of Engineering and Technology
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www.theiet.org
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0 86341 043 X
978-0-86341-043-7
IET HIsTory of TEcHnology sErIEs 6
Series Editor: Dr B. Bowers
Dr C. Hempstead
Technical History
of the Beginnings
of Radar
Other volumes in this series:
Volume 4 The history of electric wires and cables R.M. Black
Volume 6 Technical history of the beginnings of radar S.S. Swords
Volume 7 British television: the formative years R.W. Burns
Volume 9 Vintage telephones of the world P.J. Povey and R. Earl
Volume 10 The GEC research laboratories 1919–1984 R.J. Clayton and J. Algar
Volume 11 Metres to microwaves E.B. Callick
Volume 12 A history of the world semiconductor industry P.R. Morris
Volume 13 Wireless: the crucial decade 1924–34 G. Bussey
Volume 14 A scientists war – the diary of Sir Clifford Paterson 1939–45 R.J. Clayton
and J. Algar (Editors)
Volume 15 Electrical technology in mining: the dawn of a new age A.V. Jones and
R.P. Tarkenter
Volume 16 Curiosity perfectly satisfied: Faraday’s travels in Europe 1813-1815
B. Bowers and L. Symonds (Editors)
Volume 17 Michael Faraday’s ‘Chemical Notes, Hints, Suggestions and Objects of
Pursuit’ of 1822 R.D. Tweney and D. Gooding (Editors)
Volume 18 Lord Kelvin: his influence on electrical measurements and units
P. Tunbridge
Volume 19 History of international broadcasting, volume 1 J. Wood
Volume 20 The early history of radio: from Faraday to Marconi G.R.M. Garratt
Volume 21 Exhibiting electricity K.G. Beauchamp
Volume 22 Television: an international history of the formative years R.W. Burns
Volume 23 History of international broadcasting, volume 2 J. Wood
Volume 24 Life and times of Alan Dower Blumlein R.W. Burns
Volume 26 A history of telegraphy: its technology and application K.G. Beauchamp
Volume 27 Restoring Baird’s image D.F. McLean
Volume 28 John Logie Baird: television pioneer R.W. Burns
Volume 29 Sir Charles Wheatstone, 2nd edition B. Bowers
Volume 30 Radio man: the remarkable rise and fall of C.O. Stanley M. Frankland
Volume 31 Electric railways, 1880–1990 M.C. Duffy
Volume 32 Communications: an international history of the formative years R. Burns
Volume 33 Spacecraft technology: the early years M. Williamson
Technical History
of the Beginnings
of Radar
S.S. Swords
The Institution of Engineering and Technology
Published by The Institution of Engineering and Technology, London, United Kingdom
First edition © 1986 Peter Peregrinus Ltd.
Reprint with new cover © 2008 The Institution of Engineering and Technology
First published 1986
Reprinted with new cover 2008
This publication is copyright under the Berne Convention and the Universal Copyright
Convention. All rights reserved. Apart from any fair dealing for the purposes of research
or private study, or criticism or review, as permitted under the Copyright, Designs and
Patents Act, 1988, this publication may be reproduced, stored or transmitted, in any
form or by any means, only with the prior permission in writing of the publishers, or in
the case of reprographic reproduction in accordance with the terms of licences issued
by the Copyright Licensing Agency. Inquiries concerning reproduction outside those
terms should be sent to the publishers at the undermentioned address:
The Institution of Engineering and Technology
Michael Faraday House
Six Hills Way, Stevenage
Herts, SG1 2AY, United Kingdom
www.theiet.org
While the author and the publishers believe that the information and guidance given
in this work are correct, all parties must rely upon their own skill and judgement when
making use of them. Neither the author nor the publishers assume any liability to
anyone for any loss or damage caused by any error or omission in the work, whether
such error or omission is the result of negligence or any other cause. Any and all such
liability is disclaimed.
The moral right of the author to be identified as author of this work has been asserted
by him in accordance with the Copyright, Designs and Patents Act 1988.
British Library Cataloguing in Publication Data
Swords, Sean S.
Technical history of the beginnings of radar
(History of technology series no. 6)
1. Radar – History
I. Title II. Series
621.3848’09’04 TK6574.2
ISBN (10 digit) 0 86341 043 X
ISBN (13 digit) 978-0-86341-043-7
Printed in the UK by Short Run Press Ltd, Exeter
Reprinted in the UK by Lightning Source UK Ltd, Milton Keynes
To the Memory of Commandant Matt Murphy and Captain Phil Harrington
And moving thro' a mirror clear
That hangs before her all the year,
Shadows of the world appear.
There she sees the highway near,
Winding down to Camelot:
There the river eddy whirls,
And there the surly village-churls,
And the red cloaks of market girls,
Pass onward from Shalott.
Alfred Lord Tennyson
Contents
Preface xi
Acknowledgments XIII
1 Radar etymology 1
References 3
2 Radar fundamentals 5
2.1 Introduction 5
2.2 Scattering and scattering cross-section 6
2.3 Radar range equation 9
2.3.1 Pulse radar 10
2.3.2 Bistatic radar range equation 11
2.4 Multipath propagation 12
2.4.1 Electromagnetic reflection coefficient 15
2.4.2 Horizontal polarisation 16
2.4.3 Vertical polarisation 17
2.5 Multipath effects and radar coverage 17
2.5.1 Gap filling 17
2.6 Choice of polarisation 18
2.7 Fundamentals of a pulse radar system 19
2.7.1 Range and azimuth resolution 22
2.7.2 Pulse radar signals 24
2.8 Antenna duplexing - TR/ATR switches 26
2.9 Nomenclature of displays 28
2.10 Direction finding: split-beam method 30
2.11 Secondary radar 33
2.12 Over-the-horizon radar 36
2.13 Frequency bands 38
References 39
viii Contents
3 Precursors of radar 42
3.1 Introduction 42
3.2 Christian Hiilsmeyer 43
3.3 Hugo Gernsback 45
3.4 Hans Dominik 46
3.5 Nikola Tesla 47
3.6 Detection of aircraft 48
3.6.1 Ignition detection 48
3.6.2 Sound locators 48
3.6.3 Passive and active infra-red detection 49
3.7 Marconi's speech to the American Institute of Electrical
Engineers 51
3.8 Albert Hoyt Taylor and Leo Clifford Young 52
3.9 Measurement of distance 52
3.9.1 Ionospheric sounding 53
3.9.2 Geodetic surveying 59
3.9.3 Aircraft altimeters 60
3.9.3.1 Alexanderson altimeter 62
3.9.3.2 Western Electric radio altimeter 63
3.9.3.3 Altimeter of Sadahiro Matsuo of Tohoku Imperial
University, Japan 67
3.10 Three British events 68
3.10.1 O. F. Brown's memorandum 69
3.10.2 L. S. B. Alder 69
3.10.3 W. A. S. Butement and P. E. Pollard 70
3.11 Patents 74
3.12 Mystery rays 75
References 79
4 Theelebut of radar 82
4.1 Beginning of radar in Great Britain 82
4.2 Beginning of radar in Germany 91
4.3 Beginning of radar in the United States 101
4.3.1 United States Army Signal Corps 112
4.3.2 Aircraft Warning Service 118
4.3.3 Establishment of the NDRC 118
4.4 Beginning of radar in France 120
4.5 Beginning of radar in Italy 126
4.6 Beginning of radar in Japan 130
4.7 Beginning of radar in Russia 135
4.8 Beginning of radar in Holland 142
4.9 Beginning of radar in Hungary 144
Refei•enres and Rihlinpranhies 147
Contents ix
5 The British story 174
5.1 Introduction 174
5.2 Other inventors of radar 176
5.3 Air defence before the Second World War 176
5.4 The Daventry experiment 180
5.5 Development of the first radar system 186
5.5.1 Navy radar 187
5.5.2 Army radar 188
5.6 CH (Chain Home) system 188
5.6.1 Frequencies 189
5.6.2 Polarisation 197
5.6.3 Radiogoniometer 198
5.6.4 Direction finding 200
5.6.5 Height finding 201
5.6.5.1 Measurement of elevation angle 202
5.7 Transmitters 207
5.7.1 TF3 transmitter 219
5.7.2 Chain Home transmitter T3026 221
5.7.3 Transmitter circuits 222
5.7.4 Transmitter antenna arrays 225
5.7.5 Performance diagrams 229
5.8 Receivers 230
5.9 RDF beam technique - CHL and GCI 236
5.9.1 IFF and GCI 242
5.10 Airborne radar - RDF2 243
5.11 Organisation 253
5.12 Radar countermeasures 254
References 254
6 Significance of the magnetron 258
References 267
7 Conclusions 270
References 272
Appendixes
Appendix A Reciprocity principle 273
References 274
Appendix B Retarding field generators 274
References 276
Appendix C Super-regenerative receivers 276
References 278
