In message <[EMAIL PROTECTED]>, Zefram writes: >Would have been nice. Actually, since the only real significance of >GPS time is that it's part of the signal format, they could just as >well have picked an unconventional but space-efficient encoding (say, >32-bit count of seconds, wrapping every 4 Gis). I think GPS time is >best viewed as an encoding of TAI(GPS).
I have been told by a person who should know better than to tell me such things that the choice of timescale in GPS "is the result of unmitigated incompetence and the signal format is sheer stupidity". The fact that the UTC offset is in the Almanac instead of the Ephemeris means that almost all of the rapid response weapons cannot be used for tightly timed attacks until they have been primed with an almanac. He talked about the transmissions of the almanac being staggered between the satellites rather than in tandem, to reduce the mean-time to capture UTC-delta, but I did not find out if this was reality or plan. I guess one could use the "raw-dump" message to the Oncore and decode the almanac by hand to find out if this is the case. He also said that the quote in my .signature was used more often in Pentagon than he was comfortable with. Poul-Henning -- Poul-Henning Kamp | UNIX since Zilog Zeus 3.20 [EMAIL PROTECTED] | TCP/IP since RFC 956 FreeBSD committer | BSD since 4.3-tahoe Never attribute to malice what can adequately be explained by incompetence.