[time-nuts] Re: long term eLORAN time-transfer monitoring results?

[Poul-Henning Kamp]

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paul swed via time-nuts writes:

> As far as time transfer goes there should be something in the eLORAN data
> channel. But no one that I know is decoding that.

The original eLORAN on the NELS chain used the modulation described in
ITU recommendation M.589:

	https://www.itu.int/rec/R-REC-M.589/_page.print

The fundamental principle is to shift two pulses one microsecond in
opposite directions, so that the average remains constant.

The snapshot attached show the I+Q plot of that modulation, without
the eLORAN modulation, the dots would form a straight line.

I never managed to decode the data stream usefully, and years
later I learned that they transmitted "an evolution" of M.589,
without telling anybody, because they assumed they had the
only handful of receivers in the world.

I dont know if the current experiment in US/UK/FR uses that modulation.

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