2 min read

Free Hardware From the Sky? An Introduction to Tracking Weather Balloons

BSidesKC 2022 ยท SecDSM February 2023

Twice a day, radiosondes fall out of the sky around the world. Here's how to track them, find them, and repurpose their hardware.


Every day at dawn and dusk, weather services worldwide launch balloons carrying radiosondes, small sensor packages with microcontrollers, radios, and GPS, that climb to the stratosphere, burst, and parachute back down. Nobody comes to collect them. This talk covered the whole chase: how the sonde network works, receiving and decoding their telemetry with an SDR, predicting landing zones, and physically recovering the hardware.

Then the fun part, what to build once you have a pile of recovered sondes: reflashing them into trackers and experiment platforms, and the ecosystem of open-source firmware that makes it easy.

Key takeaways

  • How the global radiosonde launch network operates and why the hardware is effectively free
  • Receiving and decoding sonde telemetry with inexpensive SDR gear
  • Reflashing recovered radiosondes into useful hobby hardware

Also presented at SecDSM, February 2023.