I wrote a bit about it here: https://www.scd31.com/posts/real-time-balloon-video https://www.scd31.com/posts/real-time-balloon-video The actual bandwidth is 50

I wrote a bit about it here: https://www.scd31.com/posts/real-time-balloon-video https://www.scd31.com/posts/real-time-balloon-video The actual bandwidth is 500kbps, or about 350kbps usable after FEC. I'm encoding video at 640x480, 12FPS. It's almost entirely custom software. I'm using a Gstreamer pipeline to take in the video stream, encode it, and encapsulate it. From there, I packetize it, run it through an LDPC encoder (for error correction), data whitening, and finally send it to an FSK modem to convert it into radio waves. On the ground station I basically do the same thing in reverse. At 1W transmission, I've gotten video over 140km from a balloon to the ground. Most of that distance is horizontal - the winds tend to blow the balloon quite far. The math says the system should be good to at least 250km.