Instruction manual

PROFICIENCY IN SURVIVAL CRAFT AND RESCUE BOATS OTHER THAN
FAST RESCUE BOATS
14 17
How does it work ?
Your EPIRB contains two radio transmitters: one operating at 406 MHz
which transmits an alert which can be received by satellites, and one
operating at 121.5 MHz which transmits a signal which can be received by
overflying aircraft and Search & Rescue (SAR) homing receivers. When you
activate the EPIRB, both transmitters start broadcasting signals. Providing the
EPIRB’s batteries are in good condition, the transmission will continue for a
minimum of 48 hours.
The 406 MHz alert signal can be detected by SAR satellites. American,
European and Indian authorities operate a series of satellites in low-earth and
geostationary orbits to detect and locate aviators, mariners and land-based
users in distress. The satellites, together with a world-wide network of ground
stations and Mission Control Centres (MCC) form the International COSPAS-
SARSAT Program whose mission is to relay distress signals to the
international search and rescue community.
Ground stations track these satellites and process the distress signals to
obtain a location (by using Doppler location techniques*) of the distress. The
processed information is then forwarded to an MCC where it is combined with
other location and registration information and passed to a Rescue
Coordination Centre (RCC) which alerts the appropriate SAR authorities.
Successive satellite passes refine and confirm this information. Alternatively,
some beacons operating at the 406 MHz frequency can use the GPS system
to obtain a very accurate position. This position is then transmitted as part of
the distress signal.
The network of orbiting satellites can detect signals over the entire
surface of the earth; in addition, there are four geostationary satellites that
appear fixed in position and which detect signals over enormous areas
(approximately one-third of the surface of the earth, but excluding Polar
regions). However, the geostationary satellites, because they are fixed with
respect to the earth, cannot determine the position of the EPIRB using
Doppler.
An EPIRB should not be switched off once activated for a distress
situation until the SAR agency directs this.
DO:
- Make sure you switch on the EPIRB
- Hold the EPIRB up as high as possible.
Note: the high intensity flashing strobe light may cause discomfort if viewed
for prolonged periods.