Projects · 400 MHz
Weather Balloon Tracking & Recovery
Tracking — and when we can, recovering — the National Weather Service's ozonesonde balloons launched from Huntsville, Alabama.
How it works
The National Weather Service launches a weather balloon from the UAH SWIRLL building in Huntsville, Alabama, at 1:00 PM Central (18:00 UTC) on Saturdays. The payload measures ozone from the ground up to about 100,000 feet or more, depending on the size of the balloon. The data is transmitted on a UHF frequency and recorded so NOAA can analyze it after decoding.
The payload also carries a GPS beacon, which we use to track and find it. There's a small reward for returning a payload, but many are never found or land somewhere we can't reach. They've come down in some interesting places, which makes recoveries fun.
Note: as of March 2018, flights were cut back to once a month because of funding cuts.
Past flights
Here are pictures and flight paths from past flights. As you'll see, the predictions aren't always right, but they give us a general idea of where the balloon will go. Flight predictions are provided by Amateur Radio High Altitude Ballooning. Want to see what a NOAA ozonesonde payload looks like? Here's one up close.
Update: 2024
I don't post every flight anymore — just the ones we go out and recover. Not many flights happen these days. A few private groups still fly from time to time, but not like they used to, which is a shame.
The NWS office in Birmingham has moved its sondes to 400 MHz, so I set up a Raspberry Pi to receive them and upload the data to the internet. You can track them live on SondeHub. If you're interested in building your own, check out the radiosonde_auto_rx project on GitHub.
Here's my receive coverage area:
