S

SAD (Sum of Absolute Difference)

This acronym refers to a mathematical technique used in motion detection.

Scanning

Applied to the field of video surveillance, scanning is the panning of a camera across the horizontal field of view.

Security Camera

The traditional CCTV camera is a multipurpose device capable of numerous configurations and superb quality. They usually don't include a lens, mount, or enclosure. They also can be expensive to configure in comparison to cameras designed for a specific purpose.

Sensitivity of a surveillance camera

This term refers to the minimum level of light the CCD chip needs to generate an acceptable video picture, and is measured in lux.

Sequential switcher

A sequential switcher enables the simultaneous display or recording of multiple surveillance cameras.

Shutter speed

This is the speed which the CCD chip can read out the charge. Using dipswitches or a surveillance camera's menu (if one has been built in), the default setting of 1/50 sec (PAL) or 1/60 sec (NTSC) can be increased up to 1/100,000.

Simplex

A type of multiplexer that allows you to simultaneously record images to tape and display the live, full screen image of any individual security camera (compare this to the duplex type which can also display multiple-picture screen images while recording). A simplex multiplexer can display multiple-picture screen images, but it cannot record at the same time. Also unlike a duplex multiplexer, it is unable to record and playback recorded tapes simultaneously.

SMS (Short Message Service)

Some of the more advanced Network cameras feature software that sends notifications via the Cellular network to authorized users after programmed events. Griffid is one example of SMS being implemented in network surveillance software.

SNR (Signal-to-Noise Ratio)

SNR measures the ratio between the usable video signal and noise or interference.

Spot Cam

Spot Cams are effective security cameras, useful for general surveillance needs. They are intended to be operable out of the box (mounting bracket often not included), and most have their own integrated Varifocal lens. Be certain to choose a Spot Cam with its own auto iris feature and day/night capability.

Static IP address

An Internet Protocol (IP) address is a numerical label that is assigned to devices participating in a computer network that uses the Internet Protocol for communication between its nodes .This is an IP address that doesn't change. Any computer can connect to it, thereby making video surveillance systems with static IP addresses remotely accessible from any location on the Internet.

S-Video

R Separate Video, more commonly known as S-Video, also called Y/C, and sometimes incorrectly referred to as Super Video, is an analog video signal that carries video data as two separate signals: luma (luminance) and chroma (color).

Sync generator

This piece of equipment generates sync pulses that are used for the synchronization of surveillance cameras.

Synchronization

Frame synchronization is the process in the telecommunications transmission system to align the digital channel (time slot) at the receiving end with the corresponding time slot at the transmission end as it occurs.