An emergency locator beacon is a

radio beacon In navigation, a radio beacon or radiobeacon is a kind of beacon, a device that marks a fixed location and allows direction finding, direction-finding equipment to find relative Bearing (navigation), bearing. But instead of employing visible lig ...

, a portable battery powered

radio transmitter In electronics and telecommunications, a radio transmitter or just transmitter (often abbreviated as XMTR or TX in technical documents) is an electronic device which produces radio waves with an antenna with the purpose of signal transmissio ...

, used to locate airplanes, vessels, and persons in distress and in need of immediate rescue. Various types of emergency locator beacons are carried by aircraft, ships, vehicles, hikers and cross-country skiers. In case of an emergency, such as the aircraft crashing, the ship sinking, or a hiker becoming lost, the transmitter is deployed and begins to transmit a continuous radio signal, which is used by

search and rescue Search and rescue (SAR) is the search for and provision of aid to people who are in distress or imminent danger. The general field of search and rescue includes many specialty sub-fields, typically determined by the type of terrain the search ...

teams to quickly find the emergency and render aid. The purpose of all emergency locator beacons is to help rescuers find survivors within the so-called "golden day", the first 24 hours following a traumatic event, during which the majority of survivors can usually be saved.

Beacon types

COSPAS-SARSAT 406 MHz Distress Beacons

Cospas-Sarsat The International Cospas-Sarsat Programme is a satellite-aided search and rescue (SAR) initiative. It is organized as a treaty-based, nonprofit, intergovernmental, humanitarian cooperative of 45 nations and agencies (see infobox). It is dedica ...

is an international humanitarian consortium of governmental and private agencies which acts as a worldwide dispatcher for

operations. It operates a network of about 47

satellite A satellite or an artificial satellite is an object, typically a spacecraft, placed into orbit around a celestial body. They have a variety of uses, including communication relay, weather forecasting, navigation ( GPS), broadcasting, scient ...

s carrying radio receivers, which detect distress signals from emergency locator beacons anywhere on Earth transmitting on the international Cospas distress frequency of 406 MHz. The satellites calculate the geographic location of the beacon within 2 km by measuring the Doppler frequency shift of the radio waves due to the relative motion of the transmitter and the satellite, and quickly transmit the information to the appropriate local

first responder A first responder is a person with specialized training who is among the first to arrive and provide assistance or incident resolution at the scene of an emergency. First responders typically include Law enforcement, law enforcement officers (co ...

organizations, which perform the

. Defined officially as emergency position-indicating radiobeacon stations in the

ITU Radio Regulations The ITU Radio Regulations (RR) is a basic document of the International Telecommunication Union (ITU) that regulates on law of nations scale radiocommunication services and the utilisation of radio frequencies. It is the supplementation to th ...

(Section IV. Radio Stations and Systems – Article 1.93), these transmit a coded data burst once every 50 seconds, conforming to the C/S T.001 Specification for Cospas-Sarsat 406 MHz Distress Beacons, compatible with the Cospas-Sarsat satellite receivers. The different types include: * ELTs (emergency locator transmitters) signal aircraft distress * EPIRBs ( emergency position-indicating radio beacons) signal maritime distress * SEPIRBs (submarine emergency position-indicating radio beacons) are EPIRBs designed only for use on submarines * SSASes (ship security alert system) are used to indicate possible piracy or terrorism attacks on sea-going vessels * PLBs (personal locator beacons) are for personal use and are intended to indicate a person in distress who is away from normal

emergency services Emergency services and rescue services are organizations that ensure public safety, security, and health by addressing and resolving different emergencies. Some of these agencies exist solely for addressing certain types of emergencies, while ot ...

; e.g.,

9-1-1 911, sometimes written , is an emergency telephone number for Argentina, Canada, the Dominican Republic, Fiji, Jordan, Mexico, Pakistan, Maldives, Palau, Panama, Iraq, the Philippines, Sint Maarten, the United States, and Uruguay, as well as ...

. They are also used for crewsaving applications in shipping and lifeboats at terrestrial systems. In

New South Wales New South Wales (commonly abbreviated as NSW) is a States and territories of Australia, state on the Eastern states of Australia, east coast of :Australia. It borders Queensland to the north, Victoria (state), Victoria to the south, and South ...

, Australia, some police stations and the National Parks and Wildlife Service provide personal locator beacons to hikers for no charge.

Auxiliary maritime beacons

ENOS Rescue-System ENOS stands for "Elektronisches Notruf- und Ortungssystem" – "Electronic Rescue and Location System" - a system developed in Germany for use by divers at sea. ENOS allows people in distress to signal their location when drifting on the ocean's su ...

** A rescue beacon system designed for use by divers who have drifted away from their dive boats. *

Search and rescue transponder A search and rescue transponder (SART) is a self-contained, waterproof transponder intended for emergency use at sea. These devices may be either a radar-SART, or a GPS-based AIS-SART (automatic identification system SART). The radar-SART is u ...

(SART) ** A specialized

radar beacon Radar beacon (short: racon) is – according to ''article 1.103'' of the International Telecommunication Union, International Telecommunication Union's (ITU) ITU Radio Regulations (RR) – defined as "A transmitter-receiver associated with a fi ...

(RACON) that emits a string of 12 dots (replaced by arcs and circles when closer) for display on an X-band radar screen when scanned.

Man-overboard beacons

Personal locator beacon for divers P9170105

* MSLDs ( Maritime Survivor Locating Devices) are man-overboard signalling devices, first standardized in 2016. ** A Maritime Survivor Locator Device (MSLD) is a man-overboard locator beacon. In the U.S., rules were established in 2016 in 47 C.F.R. Part 95. A MSLD may transmit on 121.500 MHz, or one of these: 156.525 MHz, 156.750 MHz, 156.800 MHz, 156.850 MHz, 161.975 MHz, 162.025 MHz (bold are Canadian-required frequencies). *

AIS-SART An AIS-SART is a self-contained radio device used to locate a survival craft or distressed vessel by sending updated position reports using a standard Automatic Identification System (AIS) class-A position report. The position and time synchroniz ...

** A hand-held

automatic identification system The automatic identification system (AIS) is an automatic tracking system that uses transceivers on ships and is used by vessel traffic services (VTS). When satellites are used to receive AIS signatures, the term ''Satellite-AIS'' (S-AIS) is ...

(AIS) transmitter that emits only an emergency beacon. It does not have a receiver and thus cannot be a transponder.

SEND—Satellite Emergency Notification Devices

SPOT Spot or SPOT may refer to: Places * Spot, North Carolina, a community in the United States * The Spot, New South Wales, a locality in Sydney, Australia * South Pole Traverse, sometimes called the South Pole Overland Traverse People * Spot Coll ...

* inReach *

Spidertracks Spidertracks is a New Zealandbased company specialising in the development of hardware and software for the general aviation industry. The company specialises in flight tracking, aviation communication, and flight data acquisition. History ...

* Yellowbrick *

Somewear Global Hotspot A Satellite Emergency Notification Device or SEND is a portable emergency notification and locating device which uses commercial satellite systems rather than the COSPAS-SARSAT satellite system. An example of this device is SPOT. The devices use ...

Avalanche beacons

RECCO Recco (Latin: ''Ricina'' / ''Recina'') is a ''comune'' in the Metropolitan City of Genoa, region of Liguria, Italy. Recco is home to the September 8 fireworks festival honoring the Virgin Mary. The town is also known for being home to the most ...

Avalanche transceiver An avalanche transceiver or avalanche beacon is a type of emergency locator beacon, a radio transceiver (a transmitter and receiver in one unit) operating at 457 kHz for the purpose of finding people buried under snow. They are widely carrie ...

Other beacons

Mountain Locator Unit A Mountain Locator Unit or MLU was a radio transmitter for use by mountain climbers as an emergency locator beacon when the wearer needs rescue. The MLUs were simple radio beacons, and thus required search and rescuers to use traditional radio di ...

* Automatic Packet Reporting System * Crash position indicator *

Transponder (aeronautics) A transponder (short for ''trans''mitter-res''ponder'' and sometimes abbreviated to XPDR, XPNDR, TPDR or TP) is an electronic device that produces a response when it receives a radio-frequency interrogation. Aircraft have transponders to assi ...

** Can be used as an emergency beacon of sorts by setting it to squawk 7700, the distress code

References

{{Underwater diving, divequ Aircraft emergency systems Emergency communication Beacons Radio geopositioning