RADIO-LOCATION IN AUSTRALIA

Press, Volume LXXVII, Issue 23366, 27 June 1941, Page 11

RADIO-LOCATION IN AUSTRALIA

EXTENSIVE SYSTEM TO BE SET UP (Received June 27, 12.30 a.m.) CANBERRA. June 26. The Australian Minister for Air (Mr J. McEwen) announced to-day the Government’s intention to set up an extensive system of radio location to forewarn Australians of enemy raids. He said a school would be opened immediately to train the staff necessary to operate the apparatus. INTEREST IN AUSTRALIA EXPERT’S EXPLANATION F.0.0.C.) SYDNEY, June 21. The cabled news that radio-location is being use<i in Great Britain as an aid to combat German air raiders aroused considerable interest in Australia. This was heightened by the fact that an Australian. Professor Sir John Percival Madsen, professor of electrical engineering at Sydney University, had assisted in the development of radio-location. The leading authority on radio m Australia. Sir Ernest Fisk, chairman of Amalgamated Wireless (Australasia), Ltd., and Director of Economic Co-ordination in the Commonwealth explained that, while the principle o£ the device and also the method of applying it were well known,,- the development of it for its most effective use in war time, .namely, detecting the positions of raiding aeroplanes, was not surprising. ‘■‘Some years before the war, ne said, “apparatus of the kind was used in the French liner Normandie to detect the presence of icebergs or other ships in fogs. Very short.waves were used by Marconi in England 40 years ago. The present device is an extension of the same principle, for which a large number of patents have been taken out in Great Britain, the United States, and France. The waves used in the device are ■ extremely..-.short, compared with waves nearly 2000 feat long from a broadcasting station such as 2FC. “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 officially, 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. Use of Short Waves “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 aeroplane, they are reflected downwards to the earth. When they descend, they are picked up in a special receiving apparatus. The time between the sending up of the wave and its return - to earth is an extremely small fraction of a second. 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 of 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 ..my receiver can be immediately detected.. These two factors, as well as the distance along the ground, between the sending and receiving apparatus, enable an observer immediately to discover the position of an aeroplane.” Sir Ernest Fisk added that, after the war radio-location will probably be used to assist air navigation, and. with greatly increased air transportation, it should prove very useful in preventing collisions.