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Radar beacon. Racon signal as seen on a radar screen. This beacon receives using sidelobe suppression and transmits the letter "Q" in Morse code near Boston Harbor (Nahant) 17 January 1985. Radar beacon (short: racon) is – according to article 1.103 of the International Telecommunication Union's (ITU) ITU Radio Regulations (RR) [1 ...
The use of stingrays by United States law enforcement is an investigative technique used by both federal and local law enforcement in the United States to obtain information from cell phones by mimicking a cell phone tower. The devices which accomplish this are generically known as IMSI-catchers, but are commonly called stingrays, a brand sold ...
Gunfire locator. A gunfire locator or gunshot detection system is a system that detects and conveys the location of gunfire or other weapon fire using acoustic, vibration, optical, or potentially other types of sensors, as well as a combination of such sensors. These systems are used by law enforcement, security, military, government offices ...
Radio-frequency identification ( RFID) uses electromagnetic fields to automatically identify and track tags attached to objects. An RFID system consists of a tiny radio transponder called a tag, a radio receiver, and a transmitter. When triggered by an electromagnetic interrogation pulse from a nearby RFID reader device, the tag transmits ...
A permissive action link ( PAL) is an access control security device for nuclear weapons. Its purpose is to prevent unauthorized arming or detonation of a nuclear weapon. [1] The United States Department of Defense definition is: A device included in or attached to a nuclear weapon system to preclude arming and/or launching until the insertion ...
The Type Allocation Code (TAC) is the initial eight- digit portion of the 15-digit IMEI and 16-digit IMEISV codes used to uniquely identify wireless devices. The Type Allocation Code identifies a particular model (and often revision) of wireless telephone for use on a GSM, UMTS, LTE, 5G NR, iDEN, Iridium or other IMEI-employing wireless network ...
Heliograph. A heliograph (from Ancient Greek ἥλιος (hḗlios) 'sun', and γράφειν (gráphein) 'to write') is a solar telegraph [1] system that signals by flashes of sunlight (generally using Morse code) reflected by a mirror. The flashes are produced by momentarily pivoting the mirror, or by interrupting the beam with a shutter. [2]
The device numbers are enumerated in ANSI/IEEE Standard C37.2 "Standard for Electrical Power System Device Function Numbers, Acronyms, and Contact Designations". Many of these devices protect electrical systems and individual system components from damage when an unwanted event occurs such as an electrical fault.