• How does satellite TV work on planes?



    It seems like it shouldn't work at all. After all, if you have satellite at home, you know that just moving the dish a fraction of an inch can make a huge difference. How can planes get satellite TV when they're going 550 miles per hour?

    Satellite TV on planes is both extremely complex and actually somewhat simple than you think. It's similar to systems that give you satellite TV in a moving car, boat, or RV. The signal is tracked with high-speed computers and dish angles are adjusted in real time. But of course, there's a little more to a typical system than that...

    SIMPLE: An aircraft system works just like a hotel system or fitness center system. You might have noticed that you have only a few dozen channels or less, and that's because a headend system in the plane interprets the channels and sends them all to the seatback monitors. It's not like your home where you have the whole spectrum of DIRECTV channels. This technology is very mature, with the basic parts of it going back 50 years.

    COMPLEX: Planes are constantly moving in three dimensions along six axes. They tilt far more than RVs do (at least you hope) and they move up and down at different speeds. This takes a lot of computing power to accomplish since it all happens so fast. A system has to work hard to make live satellite TV work in an environment.

    SIMPLE: Tracking the satellite isn't as hard as you'd think because even if you're 30,000 feet up, that doesn't matter because the satellite is still 22,000 miles above you. Just like the things you see in the distance seem to move slower than the things you see close up, satellites move very slowly in relation to pretty much anything on the ground, even a plane moving at top speed. So, a satellite is easier to track than anything on the ground. Plus, there is no weather up there to worry about so weaker signals work better.

    COMPLEX: Satellite TV equipment must play well with other avionics. A satellite TV system must not put out any radio emissions that could potentially affect more important systems like navigation. This means even the electronics that control the system have to be specially designed. Not only that, it's much colder up at 40,000 feet so the electronics must be designed to work consistently at temperatures that could potentially damage land-based satellite equipment.

    When you look at satellite TV in the sky, it really is amazing, but with the even more amazing science we have today, it isn't as hard as you think.

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    Comments 3 Comments
    1. alnielsen's Avatar
      alnielsen -
      I am a former employee of Airfone and my son is a currently an employee of GoGo. I don't believe GoGo is going direct to satellite. They are using former Airfone towers for their connection. It works more like mobile phone technology.
    1. rad's Avatar
      rad -
      It's because of the need to continue to provide DIRECTV programming to airplanes I can see DIRECTV moving many 'core' channels from the 99/103 Ka satellites to the 101 Ku satellites when they pull the plug on SD channels in 2019. I wonder how much work the airlines are going to have to do to upgrade their systems in order to receive those channels then. Or is DIRECTV really just going to unauthorized all those residential SD receivers and keep some SD channels up on 101 to meet the needs of the airlines for programming?
    1. Stuart Sweet's Avatar
      Stuart Sweet -
      Actually there is a plan in place for that, so I wouldn't worry about it.