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  2. Radar beacon - Wikipedia

    en.wikipedia.org/wiki/Radar_beacon

    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 ...

  3. Stingray phone tracker - Wikipedia

    en.wikipedia.org/wiki/Stingray_phone_tracker

    Stingray phone tracker. The StingRay is an IMSI-catcher, a cellular phone surveillance device, manufactured by Harris Corporation. [2] Initially developed for the military and intelligence community, the StingRay and similar Harris devices are in widespread use by local and state law enforcement agencies across Canada, [3] the United States, [4 ...

  4. Permissive action link - Wikipedia

    en.wikipedia.org/wiki/Permissive_Action_Link

    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 ...

  5. Stingray use in United States law enforcement - Wikipedia

    en.wikipedia.org/wiki/Stingray_use_in_United...

    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 ...

  6. Heliograph - Wikipedia

    en.wikipedia.org/wiki/Heliograph

    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]

  7. Type Allocation Code - Wikipedia

    en.wikipedia.org/wiki/Type_Allocation_Code

    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.

  8. 3D display - Wikipedia

    en.wikipedia.org/wiki/3D_display

    3D display. A person wearing a virtual reality headset, a type of near-eye 3D display. A 3D display is a display device capable of conveying depth to the viewer. Many 3D displays are stereoscopic displays, which produce a basic 3D effect by means of stereopsis, but can cause eye strain and visual fatigue. Newer 3D displays such as holographic ...

  9. Remote viewing - Wikipedia

    en.wikipedia.org/wiki/Remote_viewing

    Remote viewing ( RV) is the practice of seeking impressions about a distant or unseen subject, purportedly sensing with the mind. [1] A remote viewer is expected to give information about an object, event, person, or location hidden from physical view and separated at some distance. [2] Physicists Russell Targ and Harold Puthoff, parapsychology ...

  10. Cloaking device - Wikipedia

    en.wikipedia.org/wiki/Cloaking_device

    A cloaking device is a hypothetical or fictional stealth technology that can cause objects, such as spaceships or individuals, to be partially or wholly invisible to parts of the electromagnetic (EM) spectrum. Fictional cloaking devices have been used as plot devices in various media for many years. Developments in scientific research [1] show ...

  11. List of astronomical instruments - Wikipedia

    en.wikipedia.org/wiki/List_of_astronomical...

    Sundial – Device that tells the time of day by the apparent position of the Sun in the sky. Telescope – Instrument that makes distant objects appear magnified. Torquetum – Medieval astronomical instrument. Triquetrum – Ancient astronomical instrument. Zenith telescope – Type of telescope that points straight up.