Instrumental Development (continued)

Figure 15 Exterior, RAAF Met. Section, Lee Point, Darwin.

Figure 16 Interior, receiver room radiosonde installation, Lee Point, RAAF Met. Section, Darwin. Australian War Memorial negative no. 044697

The wartime radiosonde, which had been in use for several years in various forms in overseas countries, consisted of a balloon equipped with very equipment for automatically recording temperature, pressure and humidity at various altitudes. This information was simultaneously transmitted to radio signals receiving units on the ground. Observation by means of a network of radiosonde stations supplemented a large volume of other weather observations to provide a wealth of meteorological detail about the South-West Pacific area. Mellor reports that:

'The first pressure charts for levels of 10,000 feet and 20,000 feet were drawn regularly at the Tropical Research Centre (RAAF Command, Brisbane), and a daily statement of the pressure pattern at each level was issued to forecasting stations.'[96]

Figure 17 Filling a radiosonde balloon with hydrogen, interior, Met. Section, Darwin. Australian War Memorial negative no. 044699

A useful side-product of radiosonde development was a battery for the airborne radiosonde unit. The plates in this battery had an infinite shelf life, and could be activated by the addition of sulphuric acid to each cell. At that time, layer—built dry cells could not be manufactured in Australia, and the shelf life of USA batteries had mostly expired by the time they were received overseas.

From an examination of RAAF files in the Australian Archives, Mitchell, ACT, it was noted that the increased load of instrument repair and maintenance necessitated in 1944, that a separate establishment be made at Sheppard House in Flinders Lane, Melbourne. This was to include provision for the calibration and maintenance of radiosondes. This section later became an important centre for testing and checking a wide range of Australian made aircraft instruments.

In charge of the instrument section from 1943 onward was Flight-Lieutenant George Elston, who was also an instructor with the Met. training section.

Bureau of Meteorology