Over on the saveitforparts YouTube channel, Gabe has uploaded a video showing how he uses a hacked TV satellite dish to receive satellite weather data from Defense Meteoroloogical Satellite Program (DMSP) satellites.
These satellites were initially developed during the Cold War and featured an encrypted downlink of meteorological data. However, recently, the DMSP downlink has encryption turned off when passing over the northern half of the USA (40°-41° latitude and up to 60° North), allowing hobbyists in some parts of the USA to decode images.
In his video, Gabe uses a HackRF SDR with an old DirectTV dish with a modified S-band helical feed mounted on a hacked Wineguard motorized platform that was originally intended for automatically pointing TV dishes on RVs. Despite some initial problems with the SatDump software crashing, he is eventually able to receive some nice, clean images.
Interestingly, Gabe also shows what the signal looks like while encrypted and how it transitions to the unencrypted signal after the satellite passes over the threshold.
We note that it is not documented by the military why encryption is being turned off only over the northern half of the USA. Still, it is speculated that the military doesn't consider images over this part of the USA to be sensitive, and disabling encryption could help save power and help other organizations with scientific research. However, as Gabe mentions in the video, being a Cold War-era satellite, the image quality from DMSP isn't great, and more modern satellites like the NOAA series give much better images over the entire earth unencrypted.