Monday, May 16, 2011
The first picture, which I took about half a century ago (in 1960 or 1961), shows what a weather balloon rig looked like in the good old days. I thought it might be of some interest to UFO crash enthusiasts.
This balloon is about to be launched from the Ocean Weather Ship Weather Watcher in the North Atlantic. The 500 gram latex balloon is held in place by a canvas cone until it is ready to be launched. Attached to the balloon is the radar reflector, made of aluminium tubing holding netting coated with metallic paint. These reflectors were opened out like umbrellas when they were to be used, and they were rather more substantial than the flimsy American ones. This is because the balloons could carry heavier loads, as they were filled with hydrogen - none of your wimpish helium here!
The man in the middle is adjusting the unwinder, which puts a suitable distance between the radio sonde canister and the balloon to prevent heat reflected or radiated from the balloon affecting the temperature readings. The canister contained a radio transmitter powered by a battery which took readings from instruments measuring pressure, temperature and relative humidity. The readings were transmitted in turn by using a revolving contact, powered by a windmill on the canister. One of the cups of the windmill can be seen on the right of the canister.
In those days it took four men to do a radiosonde ascent, after two of them had launched the balloon - the "beat" man who recorded the signals from the transmitter on graph paper, using an oscilloscope with a valve-maintained tuning fork (I hope that's quite clear?); the "comp" man, who applied corrections and turned the figures into readings of pressure, temperature and humidity; and the "winds" man, who used a plotting table to record readings of range and bearing of the balloon given by the radar operator to work out wind speeds and directions.
These days, though, the process has been largely automated. The winds are recorded using satellite navigation, and the balloons are much smaller and filled with helium, so that no special "health and safety" precautions are needed. It has become a one-man operation. Dark and lonely work . . .
The second picture, for those who are interested, is a picture taken by Bob Reid (on the right in the first picture) of Weather Watcher, which, if I remember rightly, was in James Watt Dock, Greenock.
The final picture, taken in 1960 aboard Weather Watcher, is a Portrait of the Blogger as a Young Man. As is obvious, I am "all at sea" -- as usual.