We interrupt your regularly scheduled broadcasts to tell you that the movies have been lying to you.
A trope beloved by minor supervillains, evil robots, and doom-dispensing aliens alike is the moment when they cut off your evening news broadcasts and I Love Lucy reruns to give the world a glimpse of their forthcoming plots. But, would it be quite so simple as jamming the signal and replacing? Not so says commenter LordRae, who brings us today’s comment of the day from their work in satellite transmissions:
I kind of laugh when there is a “Interruption” or someone takes over a transmission in movies and tv shows. They don’t really work like that. Sure you could throw up a carrier to the satellite and knock someone off the air (though they can track you quick if you do that) you can’t take over their feed that way. Especially if it’s encrypted you can’t do anything but try and overpower the transponder on the satellite to basically interfere with it. The ONLY way it would work like it does in the movies is if you hacked into the origination site and changed what they were sending to their dish before it got modulated and put up on air. But most uplink sites monitor those things closely and very few are able to be manipulated over the net.
Welllllll.....not quite like in the movies, but since a lot of satellites are of the “bent pipe” design, you can still cause a lot of annoyance by sending up signals that will effectively jam the desired ones. Even if you can’t actually inject a program into people’s actual television sets. (That capability died with analog broadcasting.) That was what everybody was worried would happen with “zombiesat”; fortunately, the operators were able to juggle signals around enough to keep people’s TV service going just fine.
Oh yeah you can definitely jam. Causing interference is not difficult even with a smallish amp and dish. But they will track you down if you leave it up for a while and all you really accomplish is knocking a channel or transponder off the air. One of our fly away 1 meter dishes in Afghanistan got turned on by an operator who didn’t know what he was doing and knocked a couple channels off the air for about an hour before we could reach him. He had his polarity completely off and hadn’t called for an access or a cross-polarization check.
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