■ EPIRB(Emergency Position-Indicating Radio Beacons)

406MHz beacons were specifically designed to be processed by Cospas-Sarsat satellite.
The Tron 40S is buoyant, and is designed to automatically release and activate in case of an emergency where the EPIRB and its bracket is submerged into the sea. The Tron 40S can also be operated as a manual EPIRB, by manually releasing it from its bracket.

The purpose of the Tron 40S is to give a primary alarm to the search and rescue authorities.
The EPIRB gives an immediate alarm when activated, transmitting the below-mentioned data of the ship

 in distress  

EPIRB from data

1. Country code(MID)

2. User protocol type maritime 6 numeric figures

3. 121.5MHz Radio homing device

4. CRC(Communication Research Center)

5. Beacon ID(MMSI - Hexadecimal code)

When the Tron 40S is activated(manually or automatically) it transmit on the frequencies 121.5MHz

and 406.025MHz. An analogue signal is emitted on 121.5MHz and a digital signal is transmitted on 406.025MHz. After the Tron 40S is activated, the next passing satellite will detect the transmitted signal and relay it to an antenna at a ground station, called a LUT(Local User Terminal)

For 121.5MHz signal the satellite must be within line of sight of  both the Tron 40S and a ground station.

The ground station or LUT has a 2500km satellite reception radius centered at the LUT.

In areas without LUT coverage(mostly less populated areas in the southern hemisphere), signals from the 121.5MHz transmitter will not be detected by the satellites, only by passing aircraft's. This is not the case with the 406MHz transmitter, because the satellites have a memory unit which stores the signals for relay to 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 Center(MCC). The MCC sorts the alert data according to geographic search and rescue regions and distributes

the information to the appropriate Rescue Co-ordination Center(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.

Test of EPIRB
Monthly : Float-free and manual EPIRBs to be checked using the means of provided for testing on the
equipment.

False alerts transmitted by EPIRB
False alerts are a serious problem for the rescue service. Nearly 90% of EPIRB initiated distress alerts
turn out to be false alarms.  

This EPIRB is designed to operate normally for 48 hours in extremely severe operating conditions