jotron Tron 45S, Руководство пользователя, Страница: 15 / 36

98955_UM_ 45S/SX_E 15
1.5.2 Spare parts Tron 45S
Pos.: Specification:
97812 Electronic unit, complete
97769 Battery, Tron 45S, 5 years maintenance kit
82224 Bulkhead bracket
97814 Antenna
97793 Label,
battery
98955 Users manual for Tron 45S/SX
1.6 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 18865 persons have been
rescued by the COSPAS/ SARSAT system (2004). 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 45S/SX, 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 45S/SX 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 45S/SX, 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.
1.6.1 SIGNAL DETECTION
See figure 7.1.a
When the Tron 45S/SX is activated it transmits on the frequencies 121.5 MHz and 406.025 MHz. An analogue signal
is emitted on 121.5 MHz and a digital signal is transmitted on 406.025 MHz. After the Tron 45S/SX 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 45S/SX 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.