Re: [LEAPSECS] yet another satellite time scale
Steve, Steve Allen wrote: Within the recent CGSIC proceedings is the overview presentation by Lewandowski of the BIPM. http://www.navcen.uscg.gov/cgsic/meetings/49thmeeting/Reports/%5B39%5DTiming_WL_General.pdf It includes one page plotting the various satellite time scales and another showing the Tower of Babel. With gratitude toward that presentation and the Peoples Republic of China I have enhanced my web pages to include Compass or BeiDou System Time (BST) as one of what are now three discernibly distinct broadcast time scales for navigation which run parallel to the original Ephemeris/Terrestrial Time. http://www.ucolick.org/~sla/leapsecs/deltat.html This plot is, of course, not making it clear that GPS time and Galileo System time (and perhaps others yet to come) are (at nanosecond precision) not actually the same time scale. There are more... GLONASS timescale is a three-hour offset from UTC(SU), see GLONASS ICD. WAAS, EGNOS and MSAS have their own timescales, maintained to be roughtly that of GPS. Cheers, Magnus ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
[LEAPSECS] yet another satellite time scale
Within the recent CGSIC proceedings is the overview presentation by Lewandowski of the BIPM. http://www.navcen.uscg.gov/cgsic/meetings/49thmeeting/Reports/%5B39%5DTiming_WL_General.pdf It includes one page plotting the various satellite time scales and another showing the Tower of Babel. With gratitude toward that presentation and the Peoples Republic of China I have enhanced my web pages to include Compass or BeiDou System Time (BST) as one of what are now three discernibly distinct broadcast time scales for navigation which run parallel to the original Ephemeris/Terrestrial Time. http://www.ucolick.org/~sla/leapsecs/deltat.html This plot is, of course, not making it clear that GPS time and Galileo System time (and perhaps others yet to come) are (at nanosecond precision) not actually the same time scale. In the light of all this I find myself ever more confused by the assertion that only UTC can be disseminated. Plainly there are lots of time scales being broadcast, and according to the BIPM Circular T some of the ones named UTC(k) are less stable than ones not named UTC. -- Steve Allen s...@ucolick.orgWGS-84 (GPS) UCO/Lick ObservatoryNatural Sciences II, Room 165Lat +36.99855 University of CaliforniaVoice: +1 831 459 3046 Lng -122.06015 Santa Cruz, CA 95064http://www.ucolick.org/~sla/ Hgt +250 m ___ LEAPSECS mailing list LEAPSECS@leapsecond.com http://six.pairlist.net/mailman/listinfo/leapsecs
