The European Consortium's GALILEO global navigation satellite system (GNSS) has officially activated its segment of the COPAS-SARSAT search and rescue network. In addition to their global navigation function, the GALILEO satellites in orbit also provide receivers (and transmitters) that are part of the COPAS-SARSAT (hereafter just SARSAT) system. The GALILEO satellites listen for radio signals from emergency position indicating radio beacon (EPIRB) devices. The announcement of activation was made on April 6, 2017, which, when written as 4/06 is a play on the 406-MHz frequency of the radio transmitters and receivers used in the SARSAT system.
The participation of GALILEO is similar to the U.S.A's NAVSTAR GPS, whose navigation satellites also have contained SARSAT receivers. The use of medium-earth-orbit (MEO) satellites is part of the transition of the SARSAT system to its next generation of services, called MEOSAR. The most significant improvement to be achieved in MEOSAR is a reduction in the amount of time between the transmission of an emergency radio beacon and the reception and notification to authorities of the emergency situation. Older systems using low-earth orbit (LEO) satellites required that a received emergency transmission be stored on the LEO satellite until it passed into range of a ground station to which it could forward the distress alert. This added delay to the notification of an emergency and start of any rescue effort.
A motion-picture presentation dramatizes the sequence of events that occur when a mariner activates a modern 406-MHz EPIRB:
GALILEO : Reaching you faster – when every minute matters
The return transmission to the EPIRB from the satellite shown in the dramatization won't be operational until c.2018. The EPIRB device must also provide the necessary receiver to receive the return link message.
For more background on GALILEO SARSAT, see an article from the GALILEO website at
Galileo Search and Rescue (SAR) Service
It is very interesting to note that since 1982 the SARSAT system has helped to rescue 42,000 people. That is an average of more than three people per day being aided by SARSAT. Even more information at
Galileo Search and Rescue service ready for green light!
Also see the main SARSAT website at
Articles about GPS, GLONASS, GALILEO, WAAS and other satellite navigation systems
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For more information on SARSAT MEOSAR, see my earlier article on that topic at