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Closed-circuit television
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Closed-circuit television (CCTV) 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 wireless links. CCTV is often used for surveillance in areas that may need monitoring such as banks, casinos, airports, military installations, and convenience stores.
In industrial plants, CCTV equipment may be used to observe parts of a process from a central control room; when, for example, the environment is not suitable for humans.
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Encyclopedia
Closed-circuit television (CCTV) 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 wireless links. CCTV is often used for surveillance in areas that may need monitoring such as banks, casinos, airports, military installations, and convenience stores.
In industrial plants, CCTV equipment may be used to observe parts of a process from a central control room; when, for example, 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).
Surveillance of the public using CCTV is particularly common in the UK, where there are reportedly more cameras per person than in any other country in the world. There and elsewhere, its increasing use has triggered a debate about security versus privacy.
History
The first CCTV system was installed by Siemens AG at Test Stand VII in Peenemünde, Germany in 1942, for observing the launch of V2-rockets. The noted German engineer Walter Bruch was responsible for the design and installation of the system.
CCTV recording systems are still often used at modern launch sites to record the flight of the rockets, in order to find the possible causes of malfunctions,while larger rockets are often fitted with CCTV allowing pictures of stage separation to be transmitted back to earth by radio link.
In September 1968, Olean, NY was the first city in the United States to install video cameras along its main business street in an effort to fight crime. The use of closed-circuit TV cameras piping images into the Olean Police Department propelled Olean to the forefront of crime-fighting technology.
The use of CCTV later on became very common in banks and stores to discourage theft, by recording evidence of criminal activity. Their use further popularised the concept. The first place to use CCTV in the United Kingdom was King's Lynn, Norfolk.
In recent decades, especially with general crime fears growing in the 1990s and 2000s, public space use of surveillance cameras has taken off, especially in some countries such as the United Kingdom.
Uses
Crime prevention / evidence in the UK
Outside government special facilities, CCTV was developed initially as a means of increasing security in banks. 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.
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 a massive increase in the number of CCTV systems installed. Today, systems cover most town and city centres, and many stations, car-parks and estates.
The exact number of CCTV cameras in the UK is not known but a 2002 working paper by Michael McCahill and Clive Norris of UrbanEye, based on a small sample in Putney High Street, estimated the number of surveillance cameras in private premises in London is around 500,000 and the total number of cameras in the UK is around 4,200,000.
According to their estimate the UK has one camera for every 14 people, although it has been acknowledged that the methodology behind this figure is somewhat dubious. The CCTV User Group estimate that there around 1.5 million CCTV cameras in city centres, stations, airports, major retail areas and so forth. This figure does not include the smaller surveillance systems such as those that may be found in local corner shops.
However, there is little evidence that CCTV deters crime. According to a Liberal Democrat analysis, in London "Police are no more likely to catch offenders in areas with hundreds of cameras than in those with hardly any." A 2008 Report by UK Police Chiefs concluded that only 3% of crimes were solved by CCTV.
Cameras have also been installed in taxis in the hope of deterring violence against drivers , and in mobile police surveillance vans. In some cases CCTV cameras have become a target of attacks themselves. Middlesbrough council have recently installed "Talking CCTV" cameras in their busy town-centre. It is a system pioneered in Wiltshire, which allows CCTV operators to communicate directly with the offenders they spot.
The most measurable effect of CCTV is not on crime prevention, but on a small number of high media-profile case of detection. The investigation or prosecution of several notable murder cases have been aided by the use of CCTV evidence; such as the apprehension of David Copeland, the Soho nail bomber. The use of CCTV to track the movements of missing children is now routine.
After the 7 July 2005 London bombings, CCTV footage was used to identify the bombers.
On 22 July 2005, Jean Charles de Menezes was shot dead by police at Stockwell tube station. CCTV footage debunked claims made by the Metropolitan Police in defence of the shooting of an innocent man.
Because of the bombing attempts the previous day, some of the tapes had been supposedly removed from CCTV cameras for study, and they were not functional. An ongoing change to DVR based technology may in future stop similar problems occurring.
The UK cameras were deployed and are maintained by NEP - Roll to Record, a division of NEP Broadcasting.
In the UK, CCTV is also used to target anti-social behaviour. In many areas, Local Authority CCTV works with the police to combat, for example, drink-related anti-social behaviour in town/city centres or youth-related anti social behaviour in housing estates.
Industrial processes
Industrial processes that take place under conditions dangerous for humans are today often supervised by CCTV. These are mainly processes in the chemical industry, the interior of reactors or facilities for manufacture of nuclear fuel. Use of thermographic cameras allow operators to measure the temperature of the processes. The usage of CCTV in such processes is sometimes required by law.
Traffic monitoring
Many cities and motorway networks have extensive traffic-monitoring systems, using closed-circuit television to detect congestion and notice accidents. Many of these cameras however, are owned by private companies and transmit data to drivers' GPS systems.
The London congestion charge is enforced by cameras positioned at the boundaries of and inside the congestion charge zone, which automatically read the registration plates of cars. If the driver does not pay the charge then a fine will be imposed. Similar systems are being developed as a means of locating cars reported stolen.
Transport safety
A CCTV system may be installed where an operator of a machine cannot directly observe people who may be injured by unexpected machine operation. For example, on a subway train, CCTV cameras may allow the operator to confirm that people are clear of doors before closing them and starting the train.
Operators of an amusement park ride may use a CCTV system to observe that people are not endangered by starting the ride. A CCTV camera and dashboard monitor can make reversing a vehicle safer, if it allows the driver to observe objects or people not otherwise visible.
Outside the UK
The use of CCTV in the United States is less common, though increasing, and generally meets stronger opposition. In 1998 3,000 CCTV systems were found in New York City. There are 2,200 CCTV systems in Chicago.
Privacy
Opponents of CCTV point out the loss of privacy of the people under surveillance, and the negative impact of surveillance on civil liberties. Furthermore, they argue that CCTV displaces crime, rather than reducing it. Critics often dub CCTV as "Big Brother surveillance", a reference to George Orwell's novel Nineteen Eighty-Four, which featured a two-way telescreen in every home through which The Party would monitor the populace.
More positive views of CCTV cameras have argued that the cameras are not intruding into people's privacy, as they are not surveilling private, but public space, where an individual's right to privacy can reasonably be weighed against the public's need for protection.
The recent growth of CCTV in housing areas also raises serious issues about the extent to which CCTV is being used as a social control measure rather than simply a deterrent to crime. However, since the events of September 11, 2001, many studies have suggested that public opinion of CCTV has grown more favorable. Many proponents of CCTV cite the attacks of the London Underground bombings as one example of how effective surveillance led to swift progress in post-event investigations.
Quite apart from government-permitted use (or abuse), questions are also raised about illegal access to CCTV recordings. The Data Protection Act 1998 in the United Kingdom led to legal restrictions on the uses of CCTV recordings, and also mandated their registration with the Data Protection Agency. In 2004, the successor to the Data Protection Agency, the Information Commissioner's Office clarified that this required registration of all CCTV systems with the Commissioner, and prompt deletion of archived recordings.
However subsequent case law (Durant vs. FSA) has limited the scope of the protection provided by this law, and not all CCTV systems are currently regulated. Private sector personnel in the UK who operate or monitor CCTV devices or systems are now considered security guards and have been made subject to state licensing.
A 2007 report by the UK's Information Commissioner's Office, highlighted the need for the public to be made more aware of the "creeping encroachment" into their civil liberties created by the growing use of surveillance apparatus. A year prior to the report Richard Thomas, the Information Commissioner, warned that Britain was "sleepwalking into a surveillance society".
In 2007, the UK watchdog CameraWatch claimed that the majority of CCTV cameras in the UK are operated illegally or are in breach of privacy guidelines. In response, the Information Commissioner's Office denied the claim adding that any reported abuses of the Data Protection Act are swiftly investigated.
In the United States, there are no such data protection mechanisms. It has been questioned whether CCTV evidence is allowable under the Fourth Amendment, which prohibits "unreasonable searches and seizures". The courts have generally not taken this view.
In Canada, the use of video surveillance has grown very rapidly. In Ontario, both the municipal and provincial versions of the Freedom of Information and Protection of Privacy Act outline very specific guidelines that control how images and information can be gathered by this method and/or released.
Technological developments
Computerised monitoring
The first CCTV cameras used in public spaces were crude, conspicuous, low definition black and white systems without the ability to zoom or pan. Modern CCTV cameras use small high definition colour cameras that can not only focus to resolve minute detail, but by linking the control of the cameras to a computer, objects can be tracked semi-automatically.
For example, they can track movement across a scene where there should be no movement, or they can lock onto a single object in a busy environment and follow it. Being computerised, this tracking process can also work between cameras.
The implementation of automatic number plate recognition produces a potential source of information on the location of persons or groups.
There is no technological limitation preventing a network of such cameras from tracking the movement of individuals. Reports have also been made of plate recognition misreading numbers leading to the billing of the entirely wrong person. In the UK, car cloning is a crime where, by altering, defacing or replacing their number plates with stolen ones, perpetrators attempt to avoid speeding and congestion charge fines and even to steal petrol from garage forecourts.
CCTV critics see the most disturbing extension to this technology as the recognition of faces from high-definition CCTV images. This could determine a person's identity without alerting him that his identity is being checked and logged. The systems can check many thousands of faces in a database in under a second.
The combination of CCTV and facial recognition has been tried as a form of mass surveillance, but has been ineffective because of the low discriminating power of facial recognition technology and the very high number of false positives generated. This type of system has been proposed to compare faces at airports and seaports with those of suspected terrorists or other undesirable entrants.
Computerized monitoring of CCTV images is under development, so that a human CCTV operator does not have to endlessly look at all the screens, allowing an operator to observe many more CCTV cameras. These systems do not observe people directly. Instead they track their behaviour by looking for particular types of body movement behavior, or particular types of clothing or baggage.
The theory behind this is that in public spaces people behave in predictable ways. People who are not part of the 'crowd', for example car thieves, do not behave in the same way. The computer can identify their movements, and alert the operator that they are acting out of the ordinary. Recently in the latter part of 2006, news reports on UK television brought to light newly developed technology that uses microphones in conjunction with CCTV.
If a person is observed to be shouting in an aggressive manner (e.g., provoking a fight), the camera can automatically zoom in and pinpoint the individual and alert a camera operator. Of course this then lead to the discussion that the technology can also be used to eavesdrop and record private conversations from a reasonable distance (e.g., 100 metres or about 330 feet).
The same type of system can track an identified individual as they move through the area covered by CCTV. This is being developed in the USA as part of the project co-funded by the US Defense Advanced Research Projects Agency and, in France, by a company called Keeneo. With software tools, the system is able to develop three-dimensional models of an area, and to track and monitor the movement of objects within it.
To many, the development of CCTV in public areas, linked to computer databases of people's pictures and identity, presents a serious breach of civil liberties. Critics fear the possibility that one would not be able to meet anonymously in a public place or drive and walk anonymously around a city. Demonstrations or assemblies in public places could be affected as the state would be able to collate lists of those leading them, taking part, or even just talking with protesters in the street.
Retention, storage and preservation
The long-term storage and archiving of CCTV recordings is an issue of concern in the implementation of a CCTV system. Re-usable media such as tape may be cycled through the recording process at regular intervals. There are statutory limits on retention of data.
Recordings are kept for several purposes. Firstly, the primary purpose for which they were created (e.g. to monitor a facility). Secondly, they need to be preserved for a reasonable amount of time to recover any evidence of other important activity they might document (e.g. a group of people passing a facility the night a crime was committed). Finally, the recordings may be evaluated for historical, research or other long-term information of value they may contain (e.g. samples kept to help understand trends for a business or community).
Recordings are more commonly stored using hard disk drives in lieu of video cassette recorders. The quality of digital recordings are subject to compression ratios, images stored per second, image size and duration of image retention before being overwritten. Different vendors of digital video recorders use different compression standards and varying compression ratios.
Closed-circuit digital photography (CCDP)
A development in the world of CCTV (October 2005) is in the use of megapixel digital still cameras that can take 1600 x 1200 pixel resolution images of the camera scene either on a time lapse or motion detection basis. Images taken with a digital still camera have higher resolution than those taken with a typical video camera. Relatively low-cost digital still cameras can be used for CCTV purposes, using CCDP software that controls the camera from the PC.
Images of the camera scene are transferred automatically to a computer every few seconds. Images may be monitored remotely if the computer is connected to a network.
Combinations of PIR activated floodlights with 1.3Mpix and better digital cameras are now appearing. They save the images to a flash memory card which is inserted into a slot on the device. The flash card can be removed for viewing on a computer if ever an incident happens. They are not intended for live viewing, but are a very simple and cheap "install and forget" approach to this issue.
Closed-circuit digital photography (CCDP) is more suited for capturing and saving recorded photographs, whereas closed-circuit television (CCTV) is more suitable for live monitoring purposes.
Niche uses
- The use of CCTV at Hessdalen AMS where by it is used for discovery of unidentified flying objects.
- In the earlier days of television, some programs, and selected live sporting events, were shown on closed-circuit television in theaters across the United States. The 1952 Metropolitan Opera production of Bizet's Carmen was telecast complete by NBC on closed-circuit television. From 1965-1970, the Indianapolis 500 was shown live on closed-circuit television in many movie theatres. The first few WrestleMania events were shown in such a way as well. The first six Super Bowls were shown at special closed-circuit TV gatherings in the host cities, where the game was blacked out by National Football League rules in place at the time.
- In the UK, some places have installed talking CCTV, where the operator can talk to the people they monitor.
- British author Chris Roberts quips that “Closed-Circuit Television Cameras are proving very useful to low-budget TV producers throughout the UK for programmes along the lines of World’s Rudest Drunks Outside Nightclubs in the North of England.”
CCTV countermeasures
Unless physically protected, CCTV cameras have been found to be vulnerable against a variety of (mostly illegal) tactics:
- Some people will deliberately destroy cameras. Some outdoor cameras, such as those employed by the Chicago Police Department, have bullet-resistant housing.
- Spraying substances over the lens can make the image too blurry to be read.
- Laser pointers can temporarily blind cameras, and higher powered lasers can damage them. However, since most lasers are monochromatic, colour filters can reduce the effect of laser pointers.
- For wireless networks, broadcasting a signal at the same frequency of the CCTV network is reported to be able to jam it.
See also
External links
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- from the UK Information Commissioner's Office
- National Institute of Justice Journal 249 (2003). Washington, DC: U.S. Department of Justice.
- : An independent documentary film about CCTV in the United Kingdom.
- : Case Studies
- : Examination of 20 Top Studies
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