A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Position-Finding
From: Paul Hirose
Date: 2003 Aug 9, 09:20 -0700
Jared Sherman wrote: > "But the article referenced claims a 13 second difference...which shouldn't matter if the system is correcting for it." That "if" is where the danger lies. The correction for the difference between time scales is done in software written by fallible humans. Remember the Mars mission that failed because of a misunderstanding about SI vs. US units? On the other hand, I can understand the astronomers objecting to a change in UTC. A lot of software must have been written with the assumption that UTC and UT1 would be within a second of each other. Letting the difference climb higher may break some programs. As far as I know, the Nautical Almanac still tabulates positions as a function of UT1. If not for leap seconds, we'd now be subtracting about 32 seconds to convert from UTC to almanac time. That's equivalent to 8 minutes of longitude.