The Cospas-Sarsat Geostationary Search and Rescue (GEOSAR) System

The GEOSAR system consists of 406 MHz repeaters carried on board various geostationary satellites, and the associated ground facilities called GEOLUTs which process the satellite signal.

As a GEOSAR satellite remains fixed relative to the Earth, there is no Doppler effect on the received frequency and Doppler radio location positioning techniques cannot be used to locate distress beacons. To provide rescuers with beacon position information, such information must be either:

• acquired by the beacon through an internal or an external navigation receiver and encoded in the beacon message, or

• derived, with possible delays, from the LEOSAR System.