RADIO LOCATION

New Zealand Herald, Volume LXXVIII, Issue 23996, 20 June 1941, Page 8

RADIO LOCATION

NEW BRITISH WEAPON

SEARCHING THE SKY

WARNINGS OF ATTACK

WOR IjD-WI I)E RESEARCH SYDNEY, ,Tunn 10 "I am just an ordinary scientist, and all I hope is that many more people will be able to sleep more comfortably in their beds at night-time now that the Air Ministry has released the news," said. Mr. Robert Alexander Watt, the result of whose work on "radio location" for the defence of Britain was announced yesterday by Air Chief Marshal Sir Philip Joubert. This modest comment is quoted in a cablegram from the London correspondent of the Sydney Morning Herald. Mr. Watt's research work has been in meteorology and radio, adds the correspondent. When a weather exper this silent, smiling Scot specialised in the study of thunderstorms. For a year he lived in the Sudan, so that amid the violent tropical thunderstorms he could study the effect upon radio. Experiment on Normandie

A friend of Mr. Watt said: "Thunderstorms and blitzes—these are the pet subjects of a man who has done so much for his country. interviewed in Sydney, Sir f^! K;st Fisk, chairman of Amalgamated irejess (Australasia), Limited, and Director of Economic Co-ordination in tie Commonwealth, said that, while the principle of the device and also the method of applying it were well known, the development of it for its most effective use in wartime, namely, detecting the'positions of raiding aeroplanes, was not surprising. ir ... '• Vftor the war." he added. it will probablv be used to assist air navigation, and, with greatly increased air transportation it should prove yei.v useful in preventing collisions, borne years before the war apparatus oi tinkind was used in the French liner Normandie to detect the presence of icebergs or other ships in logs. Extremely Short Waves

"Very short waves wore used by Marconi in England 1" years ago. I lie pi esent device is an extension of the same principle, for which a large number ot patents have boon taken out in Great , Britain, the United States and I< ranee, i The waves used in the device are exI tremelv short, compared with waves | nearly'2oooft. long from a broadcasting station such as 21' C, Sydney. "Whether or not Australia and -New Zealand are already manufacturing the equipment and training men for its maintenance and repair, as stated in the cablegram, cannot be revealed ofhcially, but there is nothing to prevent the device from being made and operated out here. Technical men in Australia and New Zealand are quite competent to do it. "The principle of the device is the use of very short wireless waves. A considerable number of such waves are projected into the sky, and when they strike a metal object such as an aeroi plane they are reflected downward to the earth. When they descend they : are picked up in a special receiving I apparatus. The time between the sendI ing up of the wave and its return to earth is an extremely small fraction of ia second. Telltale Angles "You can search the sky with the ! waves if you have a large number of them scattered about, and if there are any aircraft within range one. or more ot the receivers will pick up the return waves. The angle at which a wave is | sent up is known, and the angle at ! which it returns to any receiver tan | be immediately detected, j "These two factors, as well as the distance along the ground between the sending and receiving apparatus," Sir Ernest Fisk concluded, "enable an observer immediately to discover the position of an aeroplane." The military correspondent of the Svdnev Morning Herald writes: "The present publicity is afforded the project because the general scientific principle is the secret of no single country, and Britain's leadership lies in its effective practical application. "In the last few months, in America as in Britain, much work has been done on this problem, and American military experts stress the revolutionary aspects of what they call R.D.S., or the radio detection system. This extended the range of detection from the eight or nine miles of the older listening apparatus to between 50 and 75 miles, and. with bombers approaching at a third the speed of sound, it will be realised what this extra gain in time meant. Accurate Results "It is claimed that the position of an aeroplane can be detected to within a few hundred feet, even if it is up to 7o miles away. This gives ample warning of attack, it allows the course of oncoming aeroplanes to be charted, it shows the strength of the enemy squadrons, it is an invaluable aid to anti-aircraft guns, and it allows interceptors to 'ride the beam' to their quarry. "When fully developed this system —and it may he assumed that the Watt device is of much the same nature—takes away the element of surprise in ! aeriai attack and dispenses with olds fashioned sound-locating apparatus, ! searchlights, and oven patrol squadj rons. In a word, it could transmute I aerial warfare, if it lives up to its i claims." RECRUITING IN AMERICA THOUSANDS OF OPERATORS | (Reed. H.-15 p.m.) LONDON, June 19 The air attache at the British Embassy in Washington. Air Commodore George Pirio. announced to-day that he is opening offices in New York to arrange for thousands of American volunteers to go to Britain and help in operating Britain's new aircraft detectors, says a Washington despatch. Applications will be received from suitable technicians between the ages of IS and 50, who will receive attractive remuneration. They will sign on for three years or for the duration of the war, whichever is the shorter. No objection has been raised by the United States to allowing volunteers to come to Britain. An Ottawa message says that more than 2500 persons are studying radio mechanics in Canadian universities to prepare themselves for radio location work. They will lie ready to go overseas in September or October. Answering a question in the House of Commons, the Air Secretary, Sir Archibald Sinclair, said skilled men overseas whose services are available,, who possess the requisite qualifications and who are otherwise suitable, are free to enlist in the technical branches of the lighting services. However, in order to afford a wider opportunity for skilled technicians overseas to respond to the appeal broadcast by Lord Boftverhrook, the Government has decided to establish a Civilian Technical Corps, in which will be enrolled men who volunteer for service in the repair and maintenance establishments of the Navy, Armv and Air Force in a non-combatant capacity.