Radiosondes. Toys falling from the sky for some, geocaching extreme for others. Weather services, the military and others daily launch weather balloons with radiosondes attached which provide important data for weather forecasting. The radiosondes send this data and their GPS position to the ground station. The probes themselves are disposable items and fly to the ground on a parachute as soon as the weather balloon bursts.
Then comes the hour of the sonde hunters. Not only the weather service can receive the signals, but everyone with a notebook and a DVB-T stick. Who knows – maybe the signal of a radiosonde can be received exactly where you sit and read these lines right now. Sonde hunters decode the signals and head out. By car, bicycle or train. Armed with antennas, radios and long poles, they even salvage sondes from trees or rivers. They are notorious for locating and tracking sondes in the middle of nowhere in darkness, rain and wind.
About 40 radiosondes land in Germany every day. Many of them are found by sonde hunters – who are these people? The discipline has its origin in amateur radio. Such a sonde provides a great radio beacon and cross bearing can be practiced as well. Nowadays the threshold for entry has dropped – the sondes send their position located via GPS, decoding is possible with hardware which costs hardly 30,- €. There have never been better times to get into this unusual activity.
I’m happy to see you on my website, look around and when you got hooked, get an SDR stick, find launch sites near you and go hunting for objects that have touched the border to space!