On Fri, Nov 20, 2015 at 1:12 PM, Steve Allen <sla@ucolick.org> wrote:
On Fri 2015-11-20T12:55:49 -0500, Marshall Eubanks hath writ:
No, that will not work. The UTC clock is providing not just the time, but also the rotation of the Earth (UT1). An atomic clock cannot do that (not at the km level), and the tables cannot provide leap seconds (much) in advance.
The almanacs are tabulated only a couple of years in advance, and over that short an interval the current predictions of earth orientation have errors about the same as the typical human error using a sextant.
The USNO's MICA runs up to 2050, but of course does not include future UT1 variations.
Full precision already needs the DUT1 = UT1 - UTC, so if the radio broadcast time signals and almanacs could arrange to agree on a new time scale then a new difference value would preserve that ability.
Well, you could get WWV to announce UT1 - UTC offsets :) But, then, you couldn't do celestial navigation off-shore with an FM or AM radio.
Full disclosure, Marshall and I worked across the building from each
other using VLBI to measure earth orientation, so take this discussion as an example of why the ITU-R could not forge a working compromise.
It does tend to give rise to discussion... Marshall
-- Steve Allen <sla@ucolick.org> WGS-84 (GPS) UCO/Lick Observatory--ISB Natural Sciences II, Room 165 Lat +36.99855 1156 High Street Voice: +1 831 459 3046 Lng -122.06015 Santa Cruz, CA 95064 http://www.ucolick.org/~sla/ Hgt +250 m