Anemergency locator beacon is aradio beacon, a portable battery poweredradio transmitter, used tolocate 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 bysearch and rescue 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",[1] the first 24 hours following a traumatic event, during which the majority of survivors can usually be saved.
Cospas-Sarsat is an international humanitarian consortium of governmental and private agencies which acts as a worldwide dispatcher forsearch and rescue operations. It operates a network of about 47satellites 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 theDoppler 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 localfirst responder organizations, which perform thesearch and rescue.
Defined officially as emergency position-indicating radiobeacon stations in theITU Radio Regulations (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:
