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Glossary > Glossary Terms Beginning
Glossary Terms Beginning F
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: T : U
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: X : Y
- Fade margin
- The difference between the calculated or actual performance of a link and
the threshold of operation; see Threshold margin.
- Frequency division multiple access: refers to the use of multiple carriers
within the same transponder where each uplink has been assigned a frequency slot
and bandwidth, usually employed in conjunction with frequency modulation.
- Forward error correction: data correction signal added at the uplink to enhance
concealment of errors that occur on the passage of the signal via the satellite
to the downlink.
- Generic term for the feedhorn, or the feedhorn and the antenna; a generic
term for a transmission.
- Feeder link
- Backbone Earth-satellite links in contribution and distribution networks.
- In SNG, the assembly on the end of the arm extending out from the antenna
from which signals are transmitted into the focus of the antenna.
- Transmission process using mono-frequency sources of light modulated with
a signal or group of signals transmitted through a glass fibre.
- Partial scan of a frame; there are two fields in a single TV frame.
- Figure of merit
- G/T: a measure of the performance of a downlink station expressed in units
of dB/K, depending on the receive antenna and low noise amplifier combination
G (in dBi), and the amount of receiving system noise T expressed as a temperature
in kelvin (K). The higher the G/T number, the better the system.
- IEEE 1394: data transfer standard for consumer and semi-professional audio-visual
- Flange power
- The output power of the HPA delivered to the output port for delivery to the
- Electronics transit case built for ruggedness, typically made from aluminium
alloy or polypropylene, with internal shockproofing, to withstand the rigours
of shipping by air.
- Flux-gate compass
- Electronic compass.
- Transportable earth station used for SNG which can be broken down and transported
in cases to location.
- Frequency modulation.
- Arrangement of satellite coverage beams to cover a particular area; a map
of the signal strength of a satellite transponder showing the EIRP contours of
equal signal strengths as they cover the Earth's surface.
- Forward error correction
- FEC: inner convolutional coding that adds unique codes to the digital signal
at the source so errors can be detected and corrected at the destination.
- Frames per second.
- A single TV picture is referred to as a 'frame' and there are two 'fields'
in every frame.
- The number of times that an electromagnetic wave goes through a complete cycle
in one second. One cycle per second is referred to as 1 Hertz (Hz) and is the
basic measurement of frequency.
- Frequency band
- Specific span of electromagnetic spectrum.
- Frequency co-ordination
- Process to analyse and eliminate frequency interference between different
satellite systems or between terrestrial microwave systems and satellites.
- Frequency modulation
- Process whereby a carrier signal is shifted up and down in frequency ('deviates')
from its 'at rest' (centre) frequency in direct relationship to the amplitude
of the baseband signal.
- Fixed-Satellite Service: ITU designation.