Sun Surveillance, wireless solar powered video surveillance, glossary b

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.

B:

Back-focus - A procedure of adjusting the physical position of the CCD-chip/lens to achieve the correct
focus for all focal length settings (especially critical with zoom lenses).
Back porch-
1. The portion of a video signal that occurs during blanking from the end of horizontal sync to the beginning
of active video.
2. The blanking signal portion that lies between the trailing edge of a horizontal sync pulse and the trailing
edge of the corresponding blanking pulse. Color burst is located on the back porch.
Balanced signal - In CCTV this refers to a type of video signal transmission through a twisted pair cable. It
is called balanced because the signal travels through both wires, thus being equally exposed to the
external interference, so by the time the signal gets to the receiving end, the noise will be cancelled out at
the input of a differential buffer stage.
Balun - This is a device used to match or transform an unbalanced coaxial cable to a balanced twisted pair
system.
Bandwidth - The complete range of frequencies over which a circuit or electronic system can function with
minimal signal loss, usually measured to the point of less than 3 dB. In PAL systems the bandwidth limits
the maximum visible frequency to 5.5 MHz, in NTSC to 4.2 MHz. The ITU 601 luminance channel sampling
frequency of 13.5 MHz was chosen to permit faithful digital representation of the PAL and NTSC luminance
bandwidths without aliasing.
Base band - The frequency band occupied by the aggregate of the signals used to modulate a carrier
before they combine with the carrier in the modulation process. In CCTV the majority of signals are in the
baseband.
Baud - Data rate, named after Maurice Emile Baud, which generally is equal to 1 bit/s. Baud is equivalent to
bits per second in cases where each signal event represents exactly 1 bit. Typically, the baud settings of
two devices must match if the devices are to communicate with one another.
BER - Bit error rate. The ratio of received bits that are in error relative to the total number of bits received,
used as a measure of noise induced distortion in a digital bit stream. BER is expressed as a power of 10.
For example, a 1 bit error in 1 million bits is a BER of 10–6.
Betamax - Sony’s domestic video recording format, a competitor of VHS.
Bias - Current or voltage applied to a circuit to set a reference operating level for proper circuit performance,
such as the high frequency bias current applied to an audio recording head to improve linear performance
and reduce distortion.
Binary - A base 2 numbering system using the two digits 0 and 1 (as opposed to ten digits [0-9] in the
decimal system). In computer systems, the binary digits are represented by two different voltages or
currents, one corresponding to zero and another corresponding to one. All computer programs are
executed in binary form.
Bipolar - A signal containing both positive-going and negative-going amplitude. May also contain a zero
amplitude state.
B-ISDN - Broadband Integrated Services Digital Network. An improved ISDN, composed of an intelligent
combination of more ISDN channels into one that can transmit more data per second.
Bit - A contraction of binary digit. Elementary digital information that can only be 0 or 1. The smallest part of
information in a binary notation system. A bit is a single 1 or 0. A group of bits, such as 8 bits or 16 bits,
compose a byte. The number of bits in a byte depends on the processing system being used. Typical byte
sizes are 8, 16 and 32.
Bitmap (BMP) - A pixel-by-pixel description of an image. Each pixel is a separate element. Also a computer
file format.
Bit rate - Bps = Bytes per second, bps = bits per second. The digital equivalent of bandwidth, bit rate is
measured in bits per second. It is used to express the rate at which the compressed bit stream is
transmitted. The higher the bit rate, the more information that can be carried.
Black burst (color-black) - A composite color video signal. The signal has composite sync, reference
burst and a black video signal, which is usually at a level of 7.5 IRE (50 mV) above the blanking level.
Black level - A part of the video signal, close to the sync level, but slightly above it (usually 20 mV - 50 mV)
in order to be distinguished from the blanking level. It electronically represents the black part of an image,
whereas the white part is equivalent to 0.7 V from the sync level.
Blanking level - The beginning of the video signal information in the signal’s waveform. It resides at a
reference point taken as 0 V, which is 300 mV above the lowest part of the sync pulses. Also known as
pedestal, the level of a video signal that separates the range that contains the picture information from the
range that contains the synchronizing information.
Blooming - The defocusing of regions of a picture where brightness is excessive. BNC - BNC stands for
Bayonet-Neil-Councilman connector, and it is the most popular connector in CCTV and broadcast TV for
transmitting a basic bandwidth video signal over a coaxial cable.
B-picture - Bidirectional predictive coded picture; an MPEG term for a picture that is coded using motion
compensated prediction from a past and/or future reference picture.
Braid - A group of textile or metallic filaments interwoven to form a tubular structure that may be applied
over one or more wires or flattened to form a strap.
Brightness - In NTSC and PAL video signals, the brightness information at any particular instant in a
picture is conveyed by the corresponding instantaneous DC level of active video. Brightness control is an
adjustment of setup (black level, black reference).
Burst (color burst) - Seven to nine cycles (NTSC) or ten cycles (PAL) of sub-carrier placed near the end of
horizontal blanking to serve as the phase (color) reference for the modulated color sub-carrier. Burst
serves as the reference for establishing the picture color.
Bus - In computer architecture, a path over which information travels internally among various components
of a system and is available to each of the components.
Byte - A digital word made of 8 bits (zeros and ones).

Courtesy of CCTV Labs and CCTV focus magazine