jotron Tron 40GPS Mk II, User Manual

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82823_UM_ 40GPSMkII_E 17
1.2 SYSTEM DESCRIPTION
The COSPAS/SARSAT system was introduced in 1982 as a worldwide search and rescue system with the help of
satellites covering the earth’s surface. Since the introduction of the system more than 20531 persons have been rescued
by the COSPAS/ SARSAT system (2005). Currently the system consists of 5 functional
satellites in a polar orbit constellation, these satellites cover the entire earth’s surface and receive the emergency signal
from the 406 MHz transmitter within the Tron 40GPS MkII, more polar orbiting satellites will be available in the
future, giving a faster location and rescue time.
In addition several geostationary satellites are equipped with a 406 MHz transponder, these satellites are not able to
locate the Tron 40GPS MkII but will give an early warning to the rescue forces, minimising the time from an
emergency occurs till the rescue forces are at the site.
Each emergency EPIRB in the system is programmed with its own unique code, therefore it is vital that the ships data
that is given to the dealer you obtained your Tron 40GPS MkII, is correct. It is also important that your EPIRB is
registered in the database for each country. This database is normally located in the same country that the ship is
registered.
1.2.1 SIGNAL DETECTION
See figure 7.1.a
When the Tron 40GPS MkII is activated (manually or automatically) it transmits on the frequencies 121.5 MHz and
406.037 MHz. An analogue signal is emitted on 121.5 MHz and a digital signal is transmitted on 406.037 MHz. After
the Tron 40GPS MkII is activated, the next passing satellite will detect the transmitted signal and relay it to an antenna
at a ground station, called an LUT.
For the 121.5 MHz signal the satellite must be within line of sight of both the Tron 40GPS MkII and a ground station.
The ground station or LUT has a 2500 km satellite reception radius centred at the LUT. In areas without LUT coverage
(mostly less populated areas in the southern hemisphere), signals from the 121.5 MHz transmitter will not be detected
by the satellites, only by passing aircraft’s. This is not the case with the 406 MHz transmitter, because the satellites
have a memory unit, which stores the signals for relay to the next available LUT giving it a truly global coverage.
Once the signal is received by the LUT, it is processed for location and sent to a Mission Control Centre (MCC). The
MCC sorts the alert data according to geographic search and rescue regions and distributes the information to the
appropriate Rescue Co-ordination Centre (RCC), or if outside the national search and rescue area, to the appropriate
MCC that covers the area where the distress signal was detected. The RCC in turn takes the necessary action to initiate
search and rescue activities.