Questions about Austron 5000 Loran C receiver
In message 57034.12.6.201.2.1330897195.squirrel@popaccts.quikus.com, "J. Fors
ter" writes:
One option might be more, smaller, cheaper stations.
At one point, a LORAN-X (for some value of X > D) was proposed which
would use ~1kW transmitters with PRNG codes at 100kHz and give vastly
better results than LORAN-C.
It's mentioned somewhere in the ILA's archives, probably early '80ies.
The idea has been partially validated by DCF77's phase-coding.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
Hi
You still come back to what killer Loran-C in the first place - Who is going to use it?
Until somebody shuts down GPS in a big way, not a lot of drive for an alternative. I not saying that is a well thought out situation. It is indeed the position everybody has taken. It is a classic cost / risk issue. Cost is known, risk is assumed to be low / zero...
Bob
On Mar 4, 2012, at 5:50 PM, "Poul-Henning Kamp" phk@phk.freebsd.dk wrote:
In message 57034.12.6.201.2.1330897195.squirrel@popaccts.quikus.com, "J. Fors
ter" writes:
One option might be more, smaller, cheaper stations.
At one point, a LORAN-X (for some value of X > D) was proposed which
would use ~1kW transmitters with PRNG codes at 100kHz and give vastly
better results than LORAN-C.
It's mentioned somewhere in the ILA's archives, probably early '80ies.
The idea has been partially validated by DCF77's phase-coding.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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Yes, the Raynav 520 (a simple navigation receiver, not timing) undestands 4
digits GRIs but its level indicator doesn't show anything for the Lessay
chain. I have to double check the antenna and antenna preamp...
On Sun, Mar 4, 2012 at 10:53 PM, J. Forster jfor@quikus.com wrote:
Neither does the 2100F, although it does put out an RS-232 message
1/second as I remember.
-John
=============
Sorry: the 2000C doesn't directly displays TOD.
What I wish I had was an UTC seconds tick for
epoch time determination.
Kind regards,
Antonio
CT1TE
Em 2012-03-04 21:08, J. Forster escreveu:
I was not suggesting it for TOD... but as a standard of time interval
to
steer a local crystal. I've not looked at the 2000C in years, but
does it
even put out TOD?
-John
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In message F5C81892-7EBD-4F57-8131-59D8EEE21330@rtty.us, Bob Camp writes:
You still come back to what killer Loran-C in the first place -
Who is going to use it?
No, I don't particularly think Loran-C is a "killer", but until recently
it was the only feasilble backup for fragile GNSS signals.
Until somebody shuts down GPS in a big way, not a lot of drive for
an alternative.
I agree, but that doesn't make it sensible thinking :-)
I think the LightSquared fiasco made some people realize how many
eggs they put in one basket, and I'm sure the Loran-C tests needs
to be seen in that context.
But that doesn't make them a good idea: Resurrecting LORAN-C now
will never make it an economical backup to GNSS.
Instead of insisting on keeping an on-air format optimised for
staring at 1950-vintage oscilloscopes, what we need is a VLF system,
in sub/low kW power-range, based on spread-spectrum technology, with a
data-channel so receivers don't have to have a hard coded list
of all transmitters.
That would make roll-out a matter not for governments, but for
airports, harbours and other interested parties, like for instance
DME.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
I agree.
On Mon, Mar 5, 2012 at 10:24 AM, Poul-Henning Kamp phk@phk.freebsd.dkwrote:
In message F5C81892-7EBD-4F57-8131-59D8EEE21330@rtty.us, Bob Camp
writes:
You still come back to what killer Loran-C in the first place -
Who is going to use it?
No, I don't particularly think Loran-C is a "killer", but until recently
it was the only feasilble backup for fragile GNSS signals.
Until somebody shuts down GPS in a big way, not a lot of drive for
an alternative.
I agree, but that doesn't make it sensible thinking :-)
I think the LightSquared fiasco made some people realize how many
eggs they put in one basket, and I'm sure the Loran-C tests needs
to be seen in that context.
But that doesn't make them a good idea: Resurrecting LORAN-C now
will never make it an economical backup to GNSS.
Instead of insisting on keeping an on-air format optimised for
staring at 1950-vintage oscilloscopes, what we need is a VLF system,
in sub/low kW power-range, based on spread-spectrum technology, with a
data-channel so receivers don't have to have a hard coded list
of all transmitters.
That would make roll-out a matter not for governments, but for
airports, harbours and other interested parties, like for instance
DME.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
time-nuts mailing list -- time-nuts@febo.com
To unsubscribe, go to
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Poul-Henning wrote:
That would make roll-out a matter not for governments, but for
airports, harbours and other interested parties, like for instance
DME.
Would this mean depending on private parties for precision timing and
positioning [using that particular system, of course]? If so, I'm
not sure that is such a good idea. Some endeavors do not lend
themselves readily to distributed responsibility....
Best regards,
Charles
In message 20120305103136.7E0F511B984@karen.lavabit.com, "Charles P. Steinmet
z" writes:
Poul-Henning wrote:
That would make roll-out a matter not for governments, but for
airports, harbours and other interested parties, like for instance
DME.
Would this mean depending on private parties for precision timing and
positioning [using that particular system, of course]?
Well, that could be your own choice, you can tell your receiver
which transmitters you trust.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
Poul-Henning wrote (regarding the possibility of advanced, private
Loran-like systems):
Well, that could be your own choice, you can tell your receiver
which transmitters you trust.
That presumes (i) substantial sophistication on the part of the user
and (ii) possession of data that would be very hard to gather
reliably (or to trust, if popularly disseminated) -- neither of which
may be justified for the vast majority of users.
Technical merit aside, I doubt there is any chance of getting
regulatory approval for such a system, at least in the US, for
practical and political reasons.
Best regards,
Charles
In message 20120305113804.48FC411B9A8@karen.lavabit.com, "Charles P. Steinmet
z" writes:
Technical merit aside, I doubt there is any chance of getting
regulatory approval for such a system, at least in the US, for
practical and political reasons.
Indeed, it's absolutely out of the question, as you well know all
our problems these days are there isn't enough God in the constitution
or something.
Thats why some people in the military is looking into a modern
more lightweight version of "Tactical Loran" for use when GPS is jammed.
--
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk@FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
Poul-Henning wrote:
Thats why some people in the military is looking into a modern
more lightweight version of "Tactical Loran" for use when GPS is jammed.
That is a much easier thing -- our military/intelligence complex
(however oxymoronic that notion is) tries very hard to keep its
engagements well away from US soil, so (i) no regulatory approval is
required and (ii) the geographic area of the operating theater is
usually far smaller than the size of the US. So, we may very well
see the development of mobile beacons for military deployment in
hostile areas, but I very much doubt that we will ever see another
terrestrial beacon system in the US.
Best regards,
Charles