The Vaisala RS41 and RS41-SG are, currently, among the most popular Radiosonde attached to the weather balloons that are regularly launched by many different weather forecast agencies.
The radiosonde is an interesting device that has, onboard, few sensors used to get weather-related information as temperature, pressure, humidity, GPS, and some other sensors. It has also a low power TX transmitter to transmit continuously the sensor data and the GPS position.
It is usually not so difficult to find one through “radiosonde chasing”.… Read the rest