[time-nuts] improved WWVB signal being planned?
tcxo
gbusg at comcast.net
Tue Mar 29 02:14:22 UTC 2011
I'm concerned that, in their quest to address the needs of the general
public's radio clocks, NIST might overlook the frequency standards needs of
our metrology community. (Unless the metrology community provides adequate
feedback to NIST *before* it might be too late?)
According to their interpretations of ISO/IEC 17025, many customers require
metrology labs to include inter-comparison procedures for assurance. For
example, they might require a GPS disciplined house frequency standard to be
cross-checked against another non-GPS frequency standard (for assurance
purposes). In the past Loran-C served this need well as the alternate source
of traceable frequency. But with the demise of Loran-C, WWVB has become more
important for this purpose. Yes, we know that GPS out-performs WWVB for
frequency; but within a stated uncertainty (that's adequate for many
purposes), WWVB still supplies the alternate source of traceable frequency
comparison.
Do any of the resident gurus of this list have opinions as to whether or not
NIST's proposals might exclude WWVB as a source of traceable frequency
comparisons?
At least, I think it prudent that some of us let NIST know that we're still
relying on WWVB for traceable frequency comparison systems.
Greg
----- Original Message -----
From: "beale" <beale at bealecorner.com>
To: <time-nuts at febo.com>
Sent: Monday, March 28, 2011 3:02 PM
Subject: [time-nuts] improved WWVB signal being planned?
I thought this was interesting... I don't know if this had been already
mentioned here- probably some list members are already part of the process!
I wonder if this would be a spread-spectrum code like the GPS signal?
"[...] Another idea being actively investigated is to add phase modulation
to the existing WWVB signal while leaving the AM BCD code intact. This would
allow all existing devices to continue to work, but allow a new generation
of radio-controlled clocks to be developed. These new devices would have
greater processing gain and therefore be capable of reading the time code
with a lower signal-to-noise ratio."
from "We Help Move Time Through the Air
Managers of WWVB Explore Options to Improve the Service Further"
by John Lowe, manager of NIST radio stations WWV/WWVH/WWVB.
http://tf.boulder.nist.gov/general/pdf/2504.pdf
_______________________________________________
time-nuts mailing list -- time-nuts at febo.com
To unsubscribe, go to
https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts
and follow the instructions there.
More information about the time-nuts
mailing list