GAUS Radiosonde Deployment

Before a sonde is launched, it is run through a pre-flight procedure in which the telemetry is verified and radionavigation signals are acquired. Thermodynamic data - pressure, temperature, and humidity - are checked and as soon as a sufficient number of GPS satellites are acquired, the sonde can be launched. It is important to maintain clear sky view and vertical orientation to ensure the sonde GPS receiver detects the maximum number of GPS satellites available in that area at that time.

There are two launch configurations possible at any GAUS site.  The balloon can be launched (1) from a "bag" launcher, a heavy vinyl tarp that contains and protects the balloon prior to launch (used in shipboard deployments); or (2) by hand when wind and other conditions allow.

Balloons of varying weight can be used with the radiosondes. Typically, a 200-gram balloon is filled with roughly 40 cubic feet of helium, which will take a Vaisala sonde to 50 or 60 mb before the balloon bursts. The ascent rate obtained with this amount of helium and a Vaisala sonde is about 4 m/s.