Sun Surveillance, wireless solar powered video surveillance, glossary f

The Glossary

An all inclusive glossary of security lingo is provided for your convenience. This list
will undoubtedly be helpful when delving in to the realm of security.

F:

FCC - Federal Communications Commission (US).
FFT - Fast Fourier Transformation.
Fiber optics - A technology designed to transmit signals in the form of pulses of light. Fiber optic cable is
noted for its properties of electrical isolation and resistance to electrostatic and electromagnetic
interference.
Field - Refers to one-half of the TV frame that is composed of either all odd or even lines. In CCIR systems
each field is composed of 625/2 = 312.5 lines, in EIA systems 525/2 = 262.5 lines. There are 50
fields/second in CCIR/PAL, and 60 in the EIA/NTSC TV system.
Film recorder - A device for converting digital data into film output. Continuous tone recorders produce
color photographs as transparencies, prints or negatives.
Fixed focal length lens - A lens with a predetermined fixed focal length, a focusing control and a choice of
iris functions.
Flash memory - Nonvolatile, digital storage. Flash memory has slower access than SRAM or DRAM.
Flicker - An annoying picture distortion, mainly related to vertical syncs and video fields display. Some
flicker normally exists due to interlacing; more apparent in 50 Hz systems (PAL). Flicker shows also when
static images are displayed on the screen such as computer generated text transferred to video. Poor
digital image treatment, found in low-quality system converters (going from PAL to NTSC and vice versa),
creates an annoying flicker on the screen. There are several electronic methods to minimize flicker.
F-number - In lenses with adjustable irises, the maximum iris opening is expressed as a ratio (focal length
of the lens)/ (maximum diameter of aperture). This maximum iris will be engraved on the front ring of the
lens.
Focal length - The distance between the optical center of a lens and the principal convergent focus point.
Focusing control - A means of adjusting the lens to allow objects at various distances from the camera to
be sharply defined.
Foot-candela - An illumination light unit used mostly in American CCTV terminology. It equals ten times
(more precisely, 9.29) of the illumination value in luxes.
Fourier Transformation - Mathematical transformation of time domain functions into frequency domain.
Frame, (See also Field) - Refers to a composition of lines that make one TV frame. In CCIR/PAL TV system
one frame is composed of 625 lines, while in EIA/NTSC TV system of 525 lines. There are 25
frames/second in the CCIR/PAL and 30 in the EIA/NTSC TV system.
Frame store - An electronic device that digitizes a TV frame (or TV field) of a video signal and stores it in
memory. Multiplexers, fast scan transmitters, Quad compressors and even some of the latest color
cameras have built-in frame stores.
Frame switcher - Another name for a simple multiplexer, which can record multiple cameras on a single
VCR (and play back any camera in full screen) but does not have a mosaic image display.
Frame synchronizer - A digital buffer that, by storage and comparison of sync information to a reference
and timed release of video signals, can continuously adjust the signal for any timing errors.
Frame transfer (FT) - Refers to one of the three principles of charge transfer in CCD chips. The other two
are interline and frame-interline transfer.
Frame-interline transfer (FIT) - Refers to one of the few principles of charge transfer in CCD chips. The
other two are interline and frame transfer.
Frequency - The number of complete cycles of a periodic waveform that occur in a given length of time.
Usually specified in cycles per second (Hertz).
Frequency modulation (FM) - Modulation of a sine wave or carrier by varying its frequency in accordance
with amplitude variations of the modulating signal.
Front porch - The blanking signal portion that lies between the end of the active picture information and the
leading edge of horizontal sync.

Courtesy of CCTV Labs and CCTV focus magazine

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