A Personal Location Beacon (PLB) is a personal safety device designed to alert search and rescue services and allow them to quickly locate you in the event of an emergency, on land or sea. When activated it transmits a coded message on the 406 MHz distress frequency which is monitored by the Cospas-Sarsat satellite system. The alert is then relayed via an earth station to the nearest Rescue Coordination Centre (RCC). As the satellites are in a polar orbit they offer true global coverage – with a PLB you can summon help wherever you are on the planet, no matter how remote.
A PLB uses an internal GPS/GNSS receiver to pinpoint your location to within 62m. Once in the area, rescue services are then able to pinpoint your precise location using the inbuilt 121.5Mhz homing transmitter.