[time-nuts] LORAN-C reception in the UK

Poul-Henning Kamp phk at phk.freebsd.dk
Sat Jul 11 22:24:25 UTC 2015


--------
In message <55A13DAB.2030409 at rubidium.dyndns.org>, Magnus Danielson writes:

>> The reason the ERNP wasn't published, was that it concluded that 40% of
>> *all* benefits came from Loran-C, at a yearly cost only a fraction of
>> a single Galileo launch vehicle.
>
>Someone should have dreamed up the aggregate robustness of eLoran, 
>GALILEO and EGNOS.

That's exactly what the draft ERNP did.

Then they did the math and figured that with GLONASS and GPS already
being up there, Galileo didn't add nearly as much value as having
an independent robust VLF backup for all the GNSS systems.

Since a result which said that Galileo was surplus to requirements
would have been totally unacceptable, they fudged around a bit.

First they claimed that the "enhanced" Galileo signals would provide
some value which GPS and GLONASS couldn't provide, but if you read
the fine print in the notes, it basically boiled down to dual-band
precision.

Another fudge was to argue that EU could mandate that ships, planes
and trucks used Galileo, whereas they could not mandate GPS or
GLONASS, so having Galileo "potentially" improved transporation safety.

If you remove those two fudges, Loran-C provided 60-70% of the
benefit, with the rest split evenly between Galileo and AIS

>Sweden essentially had it's own set of LORAN/Chayka transmitters, with a 
>ever evolving jamming/spoofing ability. RT-02 Fredriksson was the system 
>name, often just referred to as Fredriksson.
>http://www.antus.org/RT02.html

Interesting, never heard of that before...


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Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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