About High Definition Satellite TV Programming
High-definition satellite TV programming describes a programming and transmission format characterized by a higher quality TV picture that is broadcast via satellite. Having a satellite dish does not guarantee viewers can watch high-definition (also called high def, or HD) broadcasts. HD broadcasts can also be viewed through other transmission methods.
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HD Defined
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HDTV is distinguished from standard-definition (SD) digital broadcasts and the now-obsolete SD analog broadcasting signal. HD consists of video and audio compressed and converted into a digital signal with a much higher resolution than SDTV. The number of scan lines in the picture informs how sharp and clear the image will be; a larger number of scan lines will result in a more vibrant and life-like picture. SD broadcasts are typically composed of 480 scan lines. HDTV is defined by a picture that contains a minimum of 720 horizontal scan lines of resolution, and a maximum of 1080 scan lines. This is why an HD format will be labeled 720p, 1080i or 1080p. The "p" stands for progressive scan, meaning that the 720 or 1080 scan lines are being displayed in sequence one line at a time. In contrast, the "i" stands for interlaced scan, meaning that the picture is comprised of 1,080 scan lines that are displayed separately. Half the lines, the even-numbered ones, are displayed and then the other half, the odds, are displayed. Many prefer the progressive scan because it displays a "true" 720 or 1080 lines.
Types
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Currently all commercial TV broadcasts are digital in the U.S., and all TV models made after 2009 are able to display them. TVs that can display all digital signals but require a separately purchased receiver/tuner to decode digital HD signals are known as HD-ready TVs, while more expensive TVs that are equipped with digital tuners to decode and display HD signals immediately are called integrated HDTVs.
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Satellite Defined
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Satellite television refers to the way TV programs are transmitted and carried into homes. Communication satellites are used to deliver a signal to a satellite dish and set-top box. Satellite is differentiated from cable TV that sends the signals along a radio frequency through fixed optical or coaxial cables. Cable TV can also carry both digital and HD signals. A satellite broadcast begins at a satellite uplink station owned and operated by a satellite company. Affiliated networks sell a batch of programming (such as NBC, ESPN, and many others) to the satellite companies, who compress these large chunks of data into a smaller series of binary code (zeros and ones) until they are able to be sent along the satellite transmission to orbiting satellites. According to Satellite TV HQ, the orbiting, geostationary satellites, owned in fleets by the satellite TV companies, are "positioned approximately 22,300 miles above the earth, which means that instead of circling the Earth, they follow it as it rotates." The satellites are programmed to receive the signal and send it back to Earth-bound satellite dishes. The satellite equipment communicates that the signal is intended to be received by the satellite dish installed at the customer's home. The dish "amplifies the strength of the signal, which has weakened during its journey back from space, and sends it to the satellite receiver on your TV, which decodes the signal and turns it back into images and sound."
Considerations
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HD satellite viewers will need an integrated HDTV or HD-ready TV and receiver. They will also need the satellite dish and the remote-controlled receiver (to go on top of the television) used to provide the satellite HDTV signal to the TV. This equipment is normally supplied with a subscription to a satellite service. Customers should specify that the satellite dish and programming subscription should be for HD programming.
History
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The first satellite TV signal occurred in 1962, transmitting from Europe to North America. The first public broadcast of an HD signal happened on July 23, 1996 from Raleigh, North Carolina's WRAL-HD station.
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References
Resources
- Photo Credit satellite tv dish image by Kathy Burns from Fotolia.com
