jotron Tron 40VDR, Руководство пользователя

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Tron 40VDR
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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 40VDR, is correct. It is also important that your EPIRB is registered in the data -
base for each country. This database is normally located in the same country that the
ship is registered.
1.3.1 SIGNAL DETECTION
When th e Tron 40VDR is activated
(manually or automatically) it trans -
mits 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 40VDR is activated, the
next passing satellite will detect the
transmitted signal and relay it to an
antenna at a ground station, called LUT.
The International Cospas-Sarsat System has ceased satellite processing of 121.5/243
MHz beacons from 1 February 2009.
1.3.2 DISTRESS LOCATION DETERMINATION
The location of the distress signal is determined by taking measure -
ments of the doppler shift of the EPIRB frequency when the satellite
first approach and then pass the EPIRB.
The actual frequency is heard at the time of closest approach (TCA).
Knowing the position of the satellite and using the received doppler
signal information, it is possible to determine the location of the Tron
40VDR from the satellite at the TCA. At the LUT, actually two positions
are calculated. One is the actual position (A) and the other is the mirror
image (B) position. A second satellite pass confirms the correct location (A).
Doppler-only accuracy is within 5 km (3 mi) (3.1 statute miles or 2.6 nautical miles)-
that is, the position is sufficiently accurate for SAR purposes even after only one pass.
What’s more, the most likely of the two ’mirror’ positions can be determined valid
with 98.5% accuracy after only one satellite pass. This accuracy can be increased to
99.3% using so-called ”combined Leo-Geo processing,” and this technique also enables
accurate positions to be generated with as little as two or three bursts from the
beacon (i.e. less than 4 minutes of transmission) and thus greatly increases the
chances of being found even if the beacon is ultimately consumed by fire or is
otherwise destroyed.