Major Projects

Temperature flights in the early war years were made regularly, to heights of about 18 000 feet, by aeroplanes fitted with meteorological instruments, so that on their return to earth reports of upper air conditions were made to the weather men on duty. The radiosonde, by replacing this expensive and relatively unsatisfactory method, represented an invaluable aid to forecasting. It was cheaper, faster (an average radiosonde flight occupying one hour to a height of 60 000 feet), much more valuable from a meteorological point of view because of the far greater altitude reached, and also possessing the advantage of being operative in all weathers. The latter was, naturally, most important, since temperature flights could normally only be carried out in good weather, while under bad meteorological conditions, when the need for information was greater, they could not be performed.

The first radiosonde flights in Australia were in Melbourne, in March 1941, in association with technicians from the Postmaster-General's Department. An order was placed in March 1942 for construction of the necessary equipment locally. By the end of the year, a training unit employing an American receiving set and a limited supply of transmitters, had been established at D.Met.S. headquarters in Melbourne, commencing operations in January 1943.

Satisfactory results were achieved, and since Australian built ground receivers, designed by the research laboratories of the Postmaster-General's Department, became available in March, opportunity was taken to establish daily operating radiosonde stations at Laverton, Townsville, Port Moresby, Darwin, Cloncurry and Charleville.

Lt Comm W. J. Dimitrevic, an aerologist of the United States Navy, was made available to D.Met.S. for the greater part of 1943 to assist in establishing this network, which was operating satisfactorily before the end of the year, employing locally constructed transmitters, batteries, parachutes (for return of the equipment to earth on bursting of the balloon in the rarefied upper atmosphere), balloons and test switches—all of which were developed at the instance of the instruments section of D.Met.S.

Many troubles of a technical nature were experienced in the early stages, but by the middle of 1944 the radiosonde reporting network had grown to 10 stations within Australia—at Laverton, Rathmines, Cloncurry, Charleville, Amberley, Pearce, Townsville, Darwin, Alice Springs and Parafield—for all of which operators and maintenance mechanics had been trained by the instruments section of D.Met.S.

Bureau of Meteorology