Closed-circuit television

Closed-circuit television, commonly known as CCTV, is a specialized video system used for surveillance.

Unlike broadcast television, which sends signals openly to anyone with an antenna, CCTV transmits signals to a specific, limited set of monitors. These signals can travel through wired connections or wireless links, such as point-to-multipoint or mesh networks. While almost any video camera could technically fit this definition, the term is most often used for systems designed for ongoing monitoring and security.

This technology has grown significantly, helping states monitor social behavior and helping businesses prevent crime.

The way CCTV works has changed immensely as technology has improved. Early systems required constant human monitoring because there was no way to record the footage. To store video later, engineers developed reel-to-reel media using magnetic tapes. However, this was a difficult process because operators had to manually thread the tape through the recorder. In the 1970s, the arrival of videocassette recorder technology made it much easier to record and erase information.

By the 1990s, digital multiplexing allowed a single system to record from several cameras at once. Modern systems often use digital video recorders (DVRs) or decentralized IP cameras. These IP cameras use megapixel sensors and can save data directly to network-attached storage or internal flash memory.

The history of CCTV involves many different scientific and industrial milestones. In June 1927, Russian physicist Leon Theremin developed an early mechanical system. This system used a manually operated scanning-transmitting camera and a wireless shortwave transmitter. It had a resolution of only one hundred lines. Later, in 1942, Siemens AG installed a system at Test Stand VII in Peenemünde, Nazi Germany, to observe V-2 rocket launches.

The first commercial system in the United States appeared in 1949. It was called "Vericon" and was designed by CBS Laboratories. Because it used cables instead of over-the-air signals, it did not require a government permit.

CCTV has been used for many unique purposes beyond simple security. Between 1960 and 1965, the Metropolitan Police installed systems in central London. In 1963, Munich began using the technology to monitor traffic. Interestingly, CCTV was also used for pay-per-view entertainment. People paid to watch professional boxing and wrestling in theaters or convention centers.

In 1974, the "Rumble in the Jungle" boxing match drew 50 million CCTV viewers worldwide. Just one year later, the "Thrilla in Manila" fight drew 100 million viewers. Even professional wrestling used this method, such as the WrestleMania I show in 1985, which reached over one million viewers.

In the United States, cities began using CCTV to fight crime in the late 1960s. Olean, New York, was the first city to install cameras along a main business street in 1968. In 1969, Marie Van Brittan Brown received a patent for a home security system based on CCTV. By the 1980s, surveillance spread to public areas like schools, housing projects, and parks.

In 1997 alone, New York City had 3,100 CCTV systems installed in residential areas. Many businesses, such as banks, also adopted the technology to record evidence of theft.

Researchers have studied how effective CCTV is at stopping crime, with mixed results. A 2017 review found that CCTV reduced crime by 24% to 28% in public streets and urban subway stations.

It was also found to be helpful in reducing theft in supermarkets and unruly behavior in football stadiums. However, the same study found no evidence that cameras helped in parking facilities or suburban subway stations. Some reports suggest CCTV is more effective at preventing property crimes than violent crimes. In London, a 2008 report showed that only one crime was solved per 1,000 cameras.

The rise of CCTV has created a major debate regarding the right to privacy. While cameras can help monitor dangerous industrial processes from a safe control room, they also allow for advanced social monitoring.

Some modern systems, like the "Safe City" project in Russia, can even recognize facial features and moving objects. This level of surveillance makes many people wonder how to balance public safety with individual privacy. As technology moves toward Internet-based products, these questions about monitoring and control continue to grow.