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• ground receiving stations, referred to as Local Users Terminals (LUTs),
which receive and process the satellite downlink signal to generate
distress alerts; and
• MissionControl Centers (MCCs) which receive alerts produced by LUTs
and forward them toRescueCoordinationCenters (RCCs), Search and
RescuePointsOf Contacts (SPOCs) or otherMCCs.
TheCospas-SarsatSystem includes two types of satellites:
- satellites in low-altitudeEarthorbit (LEO) which form theLEOSAR
System
- satellites in geostationary Earth orbit (GEO) which form theGEOSAR
System
Cospas-Sarsat has demonstrated that theGEOSAR andLEOSAR system
capabilities are complementary. For example theGEOSAR system can
provide almost immediate alerting in the footprint of theGEOSAR satellite,
whereas the LEOSAR system:
• provides coverage of the polar regions (which arebeyond the coverageof
geostationary satellites);
• can calculate the location of distress events usingDoppler processing
techniques; and
• is less susceptible toobstructionswhichmay block a beacon signal in a
given direction because the satellite is continuouslymovingwith respect
to the beacon.
ConceptofOperations
TheCospas-SarsatSystem candetect and locatedistress beacons that
operate at 406MHz.
Satelliteprocessingof oldanalogue technology
beacons that transmit at 121.5MHz endedon1 February2009.
Over-
flying aircraft are the onlymeans of detecting activate analogue beacons. In
some areaswithin theAustralian search and rescue region this could amount
todays rather than hours before a 121.5MHz beacon couldbe heard. In
some circumstances, the 121.5MHz beaconmay not bedetected at all.
Not all aircraft ‘listen’ to the121.5MHz frequency and those that do are
generally very high flyers. As a consequence, the search area resulting from
these detections could be very large and itwould take rescue authorities
considerable time and resources to localise thedistress signal. Thiswould
also apply to distress beacons activated directly under awell used flight path.
operations
5 – d i s tress beacons