Closed-circuit television

CCTV Cameras on building
Surveillance cameras on the corner of a building.
Dome CCTV cameras.
Dome camera in a rail station

Closed-circuit television (CCTV), also known as video surveillance,[1][2] is the use of video cameras to transmit a signal to a specific place, on a limited set of monitors. It differs from broadcast television in that the signal is not openly transmitted, though it may employ point to point (P2P), point to multipoint (P2MP), or mesh wired or wireless links. Though almost all video cameras fit this definition, the term is most often applied to those used for surveillance in areas that may need monitoring such as banks, stores, and other areas where security is needed. Though Videotelephony is seldom called "CCTV" one exception is the use of video in distance education, where it is an important tool.[3][4]

Surveillance of the public using CCTV is common in many areas around the world. In recent years, the use of body worn video cameras has been introduced as a new form of surveillance, often used in law enforcement, with cameras located on a police officer's chest or head.[5] Video surveillance has generated significant debate about balancing its use with individuals' right to privacy even when in public.[6][7]

In industrial plants, CCTV equipment may be used to observe parts of a process from a central control room, for example when the environment is not suitable for humans. CCTV systems may operate continuously or only as required to monitor a particular event. A more advanced form of CCTV, utilizing digital video recorders (DVRs), provides recording for possibly many years, with a variety of quality and performance options and extra features (such as motion detection and email alerts). More recently, decentralized IP cameras, some equipped with megapixel sensors, support recording directly to network-attached storage devices, or internal flash for completely stand-alone operation.

There are about 350 million surveillance cameras worldwide as of 2016. About 65% of these cameras are installed in Asia. The growth of CCTV has been slowing in recent years.[8]

History

Closed circuit TV monitoring at the Central Police Control Station, Munich Germany in 1973.
A typical CCTV control-room set-up, Alkmaar, Netherlands in 2007.
Desk in one of the regional control-rooms of the National Police in the Netherlands in 2017.
CCTV control-room monitor wall for 176 open-street cameras in 2017.

The first CCTV system was installed by Siemens AG at Test Stand VII in Peenemünde, Nazi Germany in 1942, for observing the launch of V-2 rockets.[9] The noted German engineer Walter Bruch was responsible for the technological design and installation of the system.[12][not in citation given]

In the U.S. the first commercial closed-circuit television system became available in 1949, called Vericon. Very little is known about Vericon except it was advertised as not requiring a government permit.[13]

Technology

The earliest video surveillance systems involved constant monitoring because there was no way to record and store information. The development of reel-to-reel media enabled the recording of surveillance footage. These systems required magnetic tapes to be changed manually, which was a time consuming, expensive and unreliable process, with the operator having to manually thread the tape from the tape reel through the recorder onto an empty take-up reel. Due to these shortcomings, video surveillance was not widespread. VCR technology became available in the 1970s, making it easier to record and erase information, and use of video surveillance became more common.[14]

During the 1990s, digital multiplexing was developed, allowing several cameras to record at once, as well as time lapse and motion-only recording. This increased savings of time and money which then led to an increase in the use of CCTV.[15]

Recently CCTV technology has been enhanced with a shift toward Internet-based products and systems, and other technological developments.[16]

Application

Closed-circuit television was used for professional boxing, as a form of pay-per-view theatre television. Boxing telecasts were broadcast live to a select number of venues, mostly theaters, where viewers paid for tickets to watch the fight live.[17][18] The first fight with a closed-circuit telecast was Joe Louis vs. Joe Walcott in 1948.[19] Closed-circuit telecasts peaked in popularity with Muhammad Ali in the 1960s and 1970s,[17][18] with "The Rumble in the Jungle" fight drawing 50 million CCTV viewers worldwide in 1974,[20] and the "Thrilla in Manila" drawing 100 million CCTV viewers worldwide in 1975.[21] Closed-circuit television was gradually replaced by pay-per-view home cable television in the 1980s and 1990s.[18]

In September 1968, Olean, New York was the first city in the United States to install video cameras along its main business street in an effort to fight crime.[22] Another early appearance was in 1973 in Times Square in New York City.[23] The NYPD installed it in order to deter crime that was occurring in the area; however, crime rates did not appear to drop much due to the cameras.[23] Nevertheless, during the 1980s video surveillance began to spread across the country specifically targeting public areas.[15] It was seen as a cheaper way to deter crime compared to increasing the size of the police departments.[23] Some businesses as well, especially those that were prone to theft, began to use video surveillance.[23] From the mid-1990s on, police departments across the country installed an increasing number of cameras in various public spaces including housing projects, schools and public parks departments.[23] CCTV later became common in banks and stores to discourage theft, by recording evidence of criminal activity. In 1998, 3,000 CCTV systems were in use in New York City.[24] A study by Nieto in 2008 found many businesses in the United States had invested heavily in video surveillance technology to protect products and promote safe workplace and consumer environments. A nationwide survey of a wide variety of companies found that 75 percent utilize CCTV surveillance. In private sector CCTV surveillance technology is operated in a wide variety of establishments such as in industry/manufacturing, retailing, financial/insurance/banking, transportation and distribution, utilities/communications, health care, and hotels/motels, parking areas, jewelry shops.

Experiments in the UK during the 1970s and 1980s, including outdoor CCTV in Bournemouth in 1985, led to several larger trial programs later that decade. The first use by local government was in King's Lynn, Norfolk, in 1987.[25] These were deemed successful in the government report "CCTV: Looking Out For You", issued by the Home Office in 1994, and paved the way for an increase in the number of CCTV systems installed. Today, systems cover most town and city centres, and many stations, car-parks and estates.

Other Languages
български: Видеонаблюдение
hrvatski: Video nadzor
Bahasa Indonesia: Televisi sirkuit tertutup
Nederlands: Cameratoezicht
日本語: 監視カメラ
српски / srpski: Видео-надзор
srpskohrvatski / српскохрватски: Video nadzor
Tiếng Việt: Camera quan sát
粵語: 閉路電視
中文: 閉路電視