Radiosonde – Windsond Swarmsonde

Swarmsonde is a radiosonde variant based on the standard radiosonde system Windsond. Swarmsonde is launched using two balloons. One balloon is cut from the sonde at a user defined altitude. The balloon that still is attached to the sonde has enough helium for the sonde to drift at the same altitude for up to an hour.

See the Swarmsonde web page for more information