The SARR receives and down-links emergency signals from aircraft and ships in distress. In addition, it provides a down-link for data received by the SARP-3. The SARR receives distress beacon signals on three separate frequencies, translates them to L-band and retransmits them to Local User Terminals (LUTs) on the ground. These terminals process the signals, determine location of the beacons, and forward this information to a rescue Mission Control Centre (MCC).

SARP-3 receives and processes emergency signals from the 406 MHz beacons of aircraft and ships in distress. It determines the name, frequency and time of the signal. These pre-processed data are then fed, in real time, to the SARR instrument for immediate transmission to SARSAT (Search And Rescue Satellite) distress terminals on the ground. This means that with a 406 MHz beacon, a distress message can be sent to the appropriate authorities, from anywhere on Earth, 24 hours a day, 365 days a year.

Since its inception in 1982 the Cospas-Sarsat System has provided distress alert information which has assisted in the rescue of more than 20,531 persons in 5,752 distress situations. In 2005 the System provided information which was used to rescue 1,666 persons in 435 distress situations.

SARR is provided by the National Oceanic and Atmospheric Administration (NOAA) and the Department of Defence Canada and developed by EMS Montreal, Canada. SARP-3 is provided by Centre National d'Études Spatiales (CNES) Toulouse, France and developed by Thales Elancourt, France, and Alcatel Alenia Space Toulouse, France.