The Science Behind Satellites
The Science Behind Satellites
By Kate Ivy and Gary Davis
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The Science Behind Your Satellite Dish
Ever wonder how your satellite system works? There’s actually quite a bit of science going on behind the scenes, with several components working together to bring you that digital-quality signal. Here’s a quick look at the pieces that form your satellite puzzle.
Your channel selection begins with the programming sources themselves. Companies like Showtime, HBO and Starz! all create their respective programming. Channel providers then purchase rights to this programming so that they can broadcast the shows via satellite. Once a provider has their programming in place, they turn their attention to the broadcast center to compress and convert the programming for satellite broadcast.
Your programming original arrives as a digital stream of video, which is then compressed and converted through an encoder, typically using the MPEG 2 format. This format reduces the overall size of the video, making it possible for a satellite to broadcast hundreds of channels at the same time.
Once encoded, the video is then encrypted so that the broadcast can only be viewed by paying subscribers. This encryption “scrambles” the signal so that those without the proper receiver pick up distorted and unintelligible video. After the video has been encrypted, it is sent to the provider’s satellite, strategically positioned in the sky.
The satellite itself uses a dish similar to your own satellite dish, to receive the video and send it back down to Earth to the provider’s subscribers. The satellite contains numerous transponders, components that allow the satellite to pick up the broadcast signal, amplify it and resend at a specific frequency. In addition to the transponders, satellites typically have several other onboard components, including a power source such as solar panels or rechargeable batteries and a computer system to monitor the satellite’s various functions and conditions.
When the satellite sends the signal back down to Earth, it is picked up by your dish, a small round antennae that receives the satellite’s broadcast and send the video on to your satellite TV receiver.
The receiver is that little black box that sits inside your home and allows you to choose which channel you want to watch. The receiver actually performs several crucial functions in the satellite viewing process, including the decryption of the signal itself. If you’ll remember, the satellite signal was scrambled by the provider to protect it from un-paying consumers. Your receiver “de-scrambles” that signal and converts the signal into a format that your television can handle, such as analog or more recently, HDTV.
Together these amazing components create a vividly clear digital picture for over 200 satellite channels. How’s that for programming genius?
About the Author
About the Authors: Gary Davis is owner of Dish Network Satellite TV and has written numerous articles on the satellite television industry. Kate Ivy has written for a variety of publications and websites and is the owner of
Ivygirl Media & Design.
Kate Ivy and Gary Davis