An EPIRB, otherwise known as a Emergency Position Indicating Radio Beacon, is a distress signal beacon used in the event of an emergency.
They are most commonly used by search and rescue teams to locate anyone who has triggered it in distress.
An example would be a ship which is sinking due to a breached hull, or an aeroplane falling to Earth with failed jet turbines.
In the event of an emergency, such as a sinking ship or an airplane crash, the EPIRB transmitter is activated and begins transmitting a continuous radio signal.
The way in which an EPIRB works is that it transmits a coded message over the free to use Cospas Sarsat satellite network.
The coded message is a transmission is a 406MHz distress frequency signal sent via satellite and earth stations to the nearest search and rescue center.
In addition, many EPIRBs also transmit a 121.5 MHz homing signal to help rescue services pinpoint the beacons location.
Many EPIRBs also have built-in GNSS receivers which provide accurate satellite tracking within ranges of +/- 50 metres.
In addition, these receivers can use a variety of GNSS such as GPS, Galileo, Glonass or a combination of multiple.
As a result, improvement in location detection speed and accuracy is achieved.
The basic purpose of this system is to help rescuers find survivors within the so-called “golden day” of the first 24 hours following a traumatic event, during which the majority of survivors can usually be saved.