Global Positioning System (Gps) - ACR Electronics RLB-33 2776 Product Support Manual

The LUT processes the Doppler-shifted signal from the LEOSAR and determines the location of the beacon, then the
LUT relays the position of the distress to a Mission Control Center (MCC) where the distress alert and location
information is immediately forwarded to an appropriate Rescue Coordination Center (RCC). The RCC dispatches
Search and Rescue (SAR) forces.
The addition of the GEOSAR satellite system greatly improves the reaction time for a SAR event. This satellite system
has no Doppler capabilities at 406 MHz, but will relay the distress alert to any of the LUT stations. When there is GPS
data included in the distress message, SAR authorities instantly know your location to within 110 yards (100 m). This
speeds up the reaction time by not having to wait for one of the LEOSAR satellite to pass overhead. Because most of
the search and rescue forces presently are not equipped to home in on the 406 MHz Satellite beacons signal, homing
must be accomplished at 121.5 MHz.
Figure 10- Satellite Coverage
Figure 11- GEOSAR Satellite Orbits
7.3

Global Positioning System (GPS)

The GPS system is a satellite group that enables a GPS receiver
to determine its exact position to within 30 m (100 ft.) anywhere
on earth. With a minimum of 24 GPS satellites orbiting the earth at
an altitude of approximately 11,000 miles they provide users with
accurate information on position, velocity, and time anywhere in
the world and in all weather conditions. The RapidFix™ stores this
data into its distress transmission allowing search and rescue
forces to narrow the search into a very small area and thus
minimize the resources required and dramatically increase the
effectiveness of the overall operation.
Figure 12 - GPS Satellite Orbits
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