Hi There have been "hardware" papers every few years showing this and that about the clocks. They obviously have access to some sort of database that lets them generate the data. I guess the database is "off limits" to civilians.
Bob On Jun 4, 2010, at 1:10 AM, [email protected] wrote: > Hi Bob, > > I have in the past watched presentations at ION on "signal in space" (SIS) > accuracy for the GPS constellation. There was a steady improvement, with > leaps between different SV (clock) generations. But also an improvements > with adjustments in the ground segment, including adding more ground > monitor sites. I am pretty sure there was also AVAR(?) plots for > individual SVs maybe only clock types. One of the presentations was from > Lookheed Martin where the new data was from II-RMs. > > http://www.ion.org/search/search_proceedings.cfm > > -- > > Björn > >> Hi >> >> That's pretty close to what I'm looking for. The ideal would be to have >> variance vs a range of tau for each individual sat. If there's a way to >> get that from the NIST site, I've overlooked it. The "whole constellation" >> data vs a range of tau is a reasonable starting point. The thing I was >> surprised by was the range of performance of each sat as shown in the >> paper I mentioned. >> >> Thanks! >> >> Bob >> >> >> On Jun 3, 2010, at 9:54 PM, Brian Kirby wrote: >> >>> I do not know if this is what your looking for, >>> http://www.nist.gov/physlab/div847/grp40/gpsarchive.cfm >>> >>> follow the directions on the date.... >>> >>> You can look at individual SVN performance, etc. >>> >>> Bob Camp wrote: >>>> Hi >>>> In this paper: >>>> TOTAL HADAMARD VARIANCE: APPLICATION TO CLOCK STEERING BY KALMAN >>>> FILTERING by Dave Howe , Ron Beard , Chuck Greenhall , Franc ̧ois >>>> Vernotte and Bill Riley >>>> http://tf.nist.gov/general/pdf/1459.pdf >>>> Figure 2 actually refers to: >>>> Navstar Quarterly Report 00-3, Space Application Branch, NRL, Wash D.C. >>>> 20 July 2000. >>>> The report apparently describes the level of variance on the various >>>> GPS satellites versus tau for the first half of 2000. Bottom line >>>> appears to be that 5x10^-13 is about as good as it gets out to 20 day >>>> tau unless you can pick your sats. Obviously this data is a bit dated. >>>> Is this data updated on a regular basis? Is it published somewhere? >>>> Can one get a look at it without risking a long term stay in Federal >>>> prison? It certainly would be useful to those trying to tweak GPSDO's. >>>> Bob >>>> _______________________________________________ >>>> time-nuts mailing list -- [email protected] >>>> To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>> >>> _______________________________________________ >>> time-nuts mailing list -- [email protected] >>> To unsubscribe, go to >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>> and follow the instructions there. >>> >> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. > > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
