Sun Surveillance, wireless solar powered video surveillance, glossary s

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.

S:

Saturation (in color) - The intensity of the colors in the active picture. The degree by which the eye
perceives a color as departing from a gray or white scale of the same brightness. A 100% saturated color
does not contain any white; adding white reduces saturation. In NTSC and PAL video signals, the color
saturation at any particular instant in the picture is conveyed by the corresponding instantaneous amplitude
of the active video sub-carrier.
Scanning - The rapid movement of the electron beam in the CRT of a monitor or television receiver. It is
formatted line-for-line across the photo-sensitive surface to produce or reproduce the video picture. When
referred to a PTZ camera, it is the panning or the horizontal camera motion.
Scanner -
1. When referring to a CCTV device it is the pan only head.
2. When referring to an imaging device it is the device with CCD chip that scans documents and images.
Scene illumination - The average light level incident upon a protected area. Normally measured for the
visible spectrum with a light meter having a spectral response corresponding closely to that of the human
eye and is quoted in lux.
Scotopic vision - Illumination levels below 10–2 lux, thus invisible to the human eye. SCSI. Small computer
systems interface. A computer standard that defines the software and hardware methods of connecting
more external devices to a computer bus.
SECAM - Sequential Couleur Avec Memoire, sequential color with memory. A color television system with
625 lines per frame (used to be 819) and 50 fields per second developed by France and the former U.S.S.
R. Color difference information is transmitted sequentially on alternate lines as an FM signal.
Serial data - Time-sequential transmission of data along a single wire. In CCTV, the most common
method of communicating between keyboards and the matrix switcher and also controlling PTZ cameras.
Serial interface. A digital communications interface in which data are transmitted and received sequentially
along a single wire or pair of wires. Common serial interface standards are RS-232 and RS-422.
Serial port - A computer I/O (input/output) port through which the computer communicates with the external
world. The standard serial port is RS-232 based and allows bidirectional communication on a relatively
simple wire connection as data flow serially.
Sidebands - The frequency bands on both sides of a carrier within which the energy produced by the
process of modulation is carried.
Signal-to-Noise ratio (S/N) - A S/N ratio can be given for the luminance signal, chrominance signal and
audio signal. The S/N ratio is the ratio of noise to actual total signal, and it shows how much higher the
signal level is than the level of noise. It is expressed in decibels (dB), and the bigger the value is, the
crisper and clearer the picture and sound will be during playback. An S/N ratio is calculated with the
logarithm of the normal signal and the noise RMS value.
Silicon - The material of which modern semiconductor devices are made. Simplex. In general, it refers to a
communications system that can transmit information in one direction only. In CCTV, simplex is used to
describe a method of multiplexer operation where only one function can be performed at a time, e.g., either
recording or playback individually.
Single-mode fiber - An optical glass fiber that consists of a core of very small diameter. A typical single-
mode fiber used in CCTV has a 9 mm core and a 125 mm outer diameter. Single-mode fiber has less
attenuation and therefore transmits signals at longer distances (up to 70 km). Such fibers are normally
used only with laser sources because of their very small acceptance cone.
Skin effect - The tendency of alternating current to travel only on the surface of a conductor as its frequency
increases.
Slow scan - The transmission of a series of frozen images by means of analog or digital signals over
limited bandwidth media, usually telephone.
Smear - An unwanted side effect of vertical charge transfer in a CCD chip. It shows vertical bright stripes in
places of the image where there are very bright areas. In better cameras smear is minimized to almost
undetectable levels.
SMPTE - Society of Motion Picture and Television Engineers.
SMPTE time code - In video editing, time code that conforms to SMPTE standards. It consists of an 8-digit
number specifying hours: minutes: seconds: frames. Each number identifies one frame on a videotape.
SMPTE time code may be of either the drop-frame or non-drop-frame type.
Snow - Random noise on the display screen, often resulting from dirty heads or weak broadcast video
reception.
S/N ratio - See Signal-to-noise ratio.
Spectrum - In electromagnetism , spectrum refers to the description of a signal’s amplitude versus its
frequency components. In optics, spectrum refers to the light frequencies composing the white light which
can be seen as rainbow colors.
Spectrum analyzer - An electronic device that can show the spectrum of an electric signal. SPG. Sync
pulse generator. A source of synchronization pulses.
Split-screen unit (quad compressor) - Equipment that simultaneously displays parts or more than one
image on a single monitor. It usually refers to four quadrants’ display.
Staircase (in television) - Same as color bars. A pattern generated by the TV generator, consisting of equal
width luminance steps of 0, +20, +40, +60, +80, and +100 IRE units and a constant amplitude chroma
signal at color burst phase. Chroma amplitude is selectable at 20 IRE units (low stairs) or 40 IRE units
(high stairs). The staircase pattern is useful for checking linearity of luminance and chroma gain,
differential gain and differential phase. Start bit. A bit preceding the group of bits representing a character
used to signal the arrival of the character in asynchronous transmission.
Sub-carrier (SC) - Also known as SC: 3.58 MHz for NTSC, 4.43 MHz for PAL. These are the basic signals in
all NTSC and PAL sync signals. It is a continuous sine wave, usually generated and distributed at 2V in
amplitude, and having a frequency of 3.579545 MHz (NTSC) and 4.43361875 MHz (PAL). Sub-carrier is
usually divided down from a primary crystal running at 14.318180 MHz, for example, in NTSC, and that
divided by 4 is 3.579545. Similar with PAL. All other synchronizing signals are directly divided down from
sub-carrier.
S-VHS - Super VHS format in video recording. A newer standard proposed by JVC, preserving the
downwards compatibility with the VHS format. It offers much better horizontal resolution up to 400 TV lines.
This is mainly due to the color separation techniques, high-quality video heads and better tapes. S-VHS is
usually associated with Y/C separated signals.
Sync - Short for synchronization pulse.
Sync generator (sync pulse generator, SPG) - Device that generates synchronizing pulses needed by
video source equipment to provide proper equipment video signal timing. Pulses typically produced by a
sync generator could be sub-carrier, burst flag, sync, blanking, H and V drives and color black. Most
commonly used in CCTV are H and V drives.

Courtesy of CCTV Labs and CCTV focus magazine

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