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From: "J. Harvey"
Subject: Re: How can a "beacon" be track down by a satellite???
X-Newsreader: Microsoft Outlook Express 6.00.2800.1123
Date: Sun, 19 Jan 2003 15:12:23 -0500
NNTP-Posting-Date: Sun, 19 Jan 2003 15:12:18 EST
Organization: Bell Sympatico
"J. Harvey" wrote:
> The older systems... the 'lost party' must crash within
> range of a ground station.
> The newer system uses GPS and you may crash anywhere
> you like.
> I don't see how that could be with EPIRB. My only experience
> (a marine "problem"), the Coast Guard chopper pilot said that a
> bird detected the signal, it was isolate to a grid square, and they
> used standard RDF to do the final. That was several (10 or so)
> years ago.
> Was he incorrect or perhaps over simplifying?
Like almost any topic, it gets complicated. The only simplification that is
inarguable is that one would definitely want to have a newer emergency
"The Cospas-Sarsat specifications for 406 MHz beacons and LEOLUTs were
amended in 1995 to provide for optionally encoding position information in
the transmitted beacon message. The resulting new generation of beacons with
this capability are referred to as location protocol beacons.
Because location protocol beacons determine and transmit their location in
the beacon message, they are able to provide rapid alerting and location
information through the Cospas-Sarsat geostationary satellite components.
Although non-location protocol beacons can provide alert information via
both the GEO and LEO satellite components; they can only be located using
the LEO satellite system and Doppler processing techniques."
"A distress signal transmitted on 121.5 MHz is lost if, on receiving it, the
satellite is not within the range of a ground station. If no ground station
is in range when a signal is transmitted on 406 MHz, the satellite will
store the signal until it can return the signal to a ground station. This
provides a means for distress calls to be heard regardless of their location
in the world."
"Local User Terminals (LUTs) are the system ground stations that receive and
process distress signals and determine the geographical location of the
Map of LUTS:
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