GLOSSARY.
Basic elements on sat system are the dish lnbf and the receiver.
Actuator
The purpose of the actuator is to provide stability to the dish while targeting (stopping at) a specific satellite on command from the satellite receiver.
Analog
A form of transmitting information characterized by continuously variable quantities, as opposed to digital transmission, which is characterized by discrete bits of information in numerical steps. An analog signal is responsive to changes in light, sound, heat and pressure
AZ/EL Mount
Antenna mount that requires two separate adjustments to move from one satellite to another
BANDWIDTH:
A specific range of frequencies
Bird
Slang for a communications satellite located in geosynchronous orbit.
C Band
This is the band between 4 and 8 GHz with the 6 and 4 GHz band being used for satellite communications.
CARRIER TO NOISE RATIO: The difference between a wanted signal and unwanted noise (CNR)
Clarke Belt
The circular orbit in space 22,237 miles from the surface of the earth at which geosynchronous satellites are placed.
Bit Error Rate
The fraction of a sequence of message bits that are in error. A bit error rate of 10-6 means that there is an average of one error per million bits
Declination Angle
Declination angle keeps satellite antenna from
aiming into deep space and changes value with
latitude in accordance to earth's curvature
Decoder
A television set-top device which enables the home subscriber to convert an electronically scrambled television picture into a viewable signal. This should not be confused with a digital coder/decoder known as a CODEC which is used in conjunction with digital transmissions
Digital
Conversion of information into bits of data for transmission through wire, fiber optic cable, satellite, or over air techniques. Method allows simultaneous transmission of voice, data or video
DISH
The dish collects the signal and focuses it at a point. The larger the dish the more signal it collects.
Downlink
The satellite to earth half of a 2 way telecommunications satellite link. Often used to describe the receive dish end of the link.
DVB
Digital Video Broadcasting - The European-backed project to harmonise adoption of digital video
EIRP
Effective Isotropic Radiated Power - This term describes the strength of the signal leaving the satellite antenna or the transmitting earth station antenna, and is used in determining the C/N and S/N. The transmit power value in units of dBW is expressed by the product of the transponder output power and the gain of the satellite transmit antenna
Elevation
The upward tilt to a satellite antenna measured in degrees required to aim the antenna at the communications satellite. When aimed at the horizon, the elevation angle is zero. If it were tilted to a point directly overhead, the satellite antenna would have an elevation of 90 degrees.
F/D
Ratio of antenna focal length to antenna diameter. A higher ratio means a shallower dish.
Focal Length
Distance from the center feed to the center of the dish
Focal Point
The area toward which the primary reflector directs and concentrates the signal received.
Footprint
A map of the signal strength showing the EIRP contours of equal signal strengths as they cover the earth's surface. Different satellite transponders on the same satellite will often have different footprints of the signal strength. The accuracy of EIRP footprints or contour data can improve with the operational age of the satellite. The actual EIRP level of the satellite, however, tends to decrease slowly as the spacecraft ages.
Forward Error Correction (FEC)
Adds unique codes to the digital signal at the source so errors can be detected and corrected at the receiver.
Frequency
The number of times that an alternating current goes through its complete cycle in one second of time. One cycle per second is also referred to as one hertz; 1000 cycles per second, one kilohertz; 1,000,000 cycles per second, one megahertz: and 1,000,000,000 cycles per second, one gigahertz
Geostationary
Refers to a geosynchronous satellite angle with zero inclination. so the satellite appears to hover over one spot on the earth's equator.
Inclination
The angle between the orbital plane of a satellite and the equatorial plane of the earth.
Ku Band
The frequency range from 10.9 to 17 GHz
Noise
Any unwanted and unmodulated energy that is always present to some extent within any signal.
MHz; Megahertz
NOISE: Unwanted electromagnetic radiation.
Parabolic Antenna
The most frequently found satellite TV antenna; it takes its name from the shape of the dish described mathematically as a parabola. The function of the parabolic shape is to focus the weak microwave signal hitting the surface of the dish into a single focal point in front of the dish. It is at this point that the feed horn is usually located.
POLARISATION:
Describes the direction of the electric field in an electromagnetic wave
Polar Mount:
Antenna mechanism permitting steering in both elevation and azimuth through rotation about a single axis.
RF: Radio Frequency
Polarization or Polarity
A technique used by the satellite designer to increase the capacity of the satellite transmission channels by reusing the satellite transponder frequencies. In linear cross polarization schemes, half of the transponders beam their signals to earth in a vertically polarized mode; the other half horizontally polarizes their down links. Although the two sets of frequencies overlap, they are 90 degree out of phase, and will not interfere with each other. To successfully receive and decode these signals on earth, the earth station must be outfitted with a properly polarized feed horn to select the vertically or horizontally polarized signals as desired.
Satellite
A sophisticated electronic communications relay station orbiting 22,237 miles above the equator moving in a fixed orbit at the same speed and direction of the earth (about 7,000 mph east to west).
Skew
An adjustment that compensates for slight variance in angle between identical senses of polarity generated by two or more satellites.
Spectrum
The range of electromagnetic radio frequencies used in transmission of voice, data and television.
SPLITTER: A passive device with one input and two or more outputs.
Transponder
A combination receiver, frequency converter, and transmitter package, physically part of a communications satellite. Transponders have a typical output of five to ten watts, operate over a frequency band with a 36 to 72 megahertz bandwidth in the L, C, Ku, and sometimes Ka Bands or in effect typically in the microwave spectrum, except for mobile satellite communications. Communications satellites typically have between 12 and 24 onboard transponders although the INTELSAT VI at the extreme end has 50.
Special thanks to the original author of this post adp81