search and rescue satellite aided tracking (GPS, Galileo) (COSPAS-SARSAT)
COSPAS-SARSAT is a satellite-based search and rescue system dating back to the 1980s. It is an international maritime distress system with Russian participation. The acronym COSPAS is derived from Russian and means Space System for the Search of Vessels in Distress, and the acronym SARSAT stands for Search and Rescue Satellite Aided Tracking.
The Cospas-Sarsat system can be used to locate vessels and persons in distress using a distressbeacon or by means of a radio buoy, Emergency Position Indication Radio Beacon( EPIRB). The Cospas-Sarsat system operates with six LEO satellites, LEOSAR, and five GEO satellites, GEOSAR, which can receive distress signals from distress transmitters and use them to calculate the coordinates of the distress victim. The emergency beacon frequencies used to transmit at 121 MHz, 243 MHz, or 406 MHz. The two lower frequencies have been discontinued, so that only the international emergency radio frequency of 406 MHz is now used for transmission.
Unlike Galileo 's Search and Rescue( SAR) service, the emergency signals received by Cospas-Sarsat are not acknowledged. The person seeking help therefore has no knowledge of whether the distress signals have been received. In addition, the positioning accuracy of the system developed in the 1980s is in the kilometer range and the response time is over an hour. This is due to the fact that the low-flying Leosar satellites fly over every point on Earth within 45 to 60 minutes at the latest.