So what can you do with a radiosonde if you find one? They can be reprogrammed with custom firmware (like https://github.com/mikaelnousiainen/RS41ng) and repurposed for amateur radio use. I am not sure whether it is a cost effective option given the many cheap ESP32-based boards available now, but appealing to reuse and recycle the waste from disposable sensors going up hundreds of times a day.
For now this one will sit as a trophy in my office though.
Custom firmware for Vaisala RS41 and Graw DFM-17 radiosondes with support for amateur radio use. Ideal for tracking high-altitude balloons. Supported modes include APRS, Horus 4FSK mode, CATS, mors...
If you are interested in finding radiosondes in your area, you can track them on https://sondehub.org
I was also running a little LoRa32 board with MySondy firmware (https://github.com/MirkoDalmonte/MySondyGO-Release), which helped a lot to pinpoint it in the field after it was too low for other sites to get locations.
I recovered my first radiosonde today! Launched from Spokane, this one landed close enough to town to try to follow it, but a bit farther than predicted, so I chased it into Idaho. It landed behind a farmer's field, he drove me back in his four-wheeler to recover it after I explained what I was looking for. He may have been somewhat amused that I was looking for it on purpose, he has found them on his land before while working the fields.
Got wet socks when searching for this radiosonde, (T4820741) eventually found it! It has been long time since last search. Sondehunting just a nice reason to go out to breath some forest air.
#radiosonde #sonde #radiosondi #sond #radiosond #vaisala #sääilmapallo #weatherballoon #hab
@xssfox
Video of #Horus Binary for those interested being RX'd on a #Icom IC7000 (my main shack rig) , I had accidentally forgot to put - before my latitude co-ords "putting me somewhere in japan" as quoted by @autumnal ,,,oops 
)
This was super fun and we really look forward to another launch it was a pleasure to be apart of the team to make this happen!
#radiosonde #sondehub #amateurradio #hamradio
Kelsey Jordahl
Patrick ON4CDJ
Jouni OH3CUF
adorfer
Forest.
Craig Askings