Technology: Search and Rescue (SAR)/Galileo Service
Global Search and Rescue (SAR) operations quickly locate and help people in distress. The SAR/Galileo service, launched on 15 December 2016 as part of Galileo Initial Services, contributes to these live-saving efforts by swiftly relaying radio beacon distress signals to the relevant SAR crews by means of dedicated payloads on-board Galileo satellites, supported by three ground stations strategically deployed across Europe. On 21 January 2020, the SAR/Galileo Return Link Service (RLS) was declared operational. Now, Galileo not only locates people in distress and makes their position known to the relevant authorities, the SAR/Galileo RLS provides an automatic acknowledgement message back to the user informing them that their request for help has been received.
How the SAR/Galileo service works
The SAR/Galileo service is the biggest contributor to the Cospas-Sarsat MEOSAR programme in terms of ground segment and space segment assets. It provides the following two services:
These SAR/Galileo services are fully integrated into the Cospas-Sarsat system. The SAR transponder on Galileo satellites picks up signals emitted from distress beacons in the 406 – 406.1MHz band and broadcasts this information to dedicated ground stations (MEOLUTs) in the L-band at 1544.1MHz. These downlink signals transmitted by the Galileo SAR payloads are used by the MEOLUTs to generate an independent location of the beacon, which is then relayed to first responders through dedicated Cospas-Sarsat Mission Control Centres.
What is Cospas-Sarsat?
Cospas-Sarsat is a non-profit satellite-based search and rescue distress alert detection and information distribution system. It provides accurate, timely and reliable distress alert and location data to SAR authorities, increasing the survival chances for people in distress by reducing the time it takes to locate them and relay this information to responders.
Established in 1979 by Canada, France, the USA and the former Soviet Union, the Cospas-Sarsat Programme currently has 45 countries and organisations that maintain, coordinate and operate the interoperable ground and space segments in line with Cospas-Sarsat specifications and performance standards.
The system is available to maritime and aviation users and to individual persons in distress situations on a non-discriminatory basis. It is free of charge for the end-user. The figure below shows the main components of the system:
What it means for you
With contributions from Galileo and other GNSS providers, Cospas-Sarsat has been able to transition from its original design based on satellites in low Earth orbits (LEOSAR), later complemented by geostationary orbit satellites (GEOSAR), towards MEOSAR, a solution based on medium orbit satellites such as Galileo.
The MEOSAR system offer the advantages of both the LEOSAR and GEOSAR systems without their limitations by providing transmission of the distress message and independent location of the beacon, with near-real-time worldwide coverage. Users benefit from:
With the introduction of the Return Link Service (RLS) Galileo became an even greater differentiator in search and rescue operations. The RLS relies on Galileo’s E1 navigation signal and is available worldwide for RLS-enabled beacons. Thanks to the improvements offered by the SAR/Galileo service, more lives are being saved.
Source: Galileo Search and Rescue Service