Emergency position-indicating radiobeacon station

Emergency position-indicating radiobeacon station (short: EPIRS) is – according to Article 1.93 of the International Telecommunication Union's (ITU) Radio Regulations (RR) – defined as «A station in the mobile service the emissions of which are intended to facilitate search and rescue operations.»

Each station shall be classified by the service in which it operates permanently or temporarily.

General description

EPIRB are tracking transmitters which aid in the detection and location of boats, aircraft, and people in distress. A PLB (Personal Locator Beacon) is particular type of EPIRB that is typically smaller, has a shorter battery life and unlike a proper EPIRB is registered to a person rather than a vessel. The terminology ELB (Emergency Locator Beacon) is used interchangably with EPIRB only when used on aircraft. Strictly, they are radiobeacons that interface with worldwide offered service of Cospas-Sarsat, the international satellite system for search and rescue (SAR). When manually activated, or automatically activated upon immersion or impact, such beacons send out a distress signal. The signals are monitored worldwide and the location of the distress is detected by non-geostationary satellites doppler trilateration and in more recent EPIRBs also by GPS.