Date: Sun, 31 Mar 2002 13:25:49 -0700 (MST) From: "M. Warner Losh" <imp@village.org> To: dp@penix.org Cc: hackers@FreeBSD.ORG Subject: Re: GPS time. Message-ID: <20020331.132549.127506348.imp@village.org> In-Reply-To: <Pine.LNX.4.43L0.0203291757560.4473-100000@saruman.xwin.net> References: <Pine.LNX.4.43L0.0203291757560.4473-100000@saruman.xwin.net>
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In message: <Pine.LNX.4.43L0.0203291757560.4473-100000@saruman.xwin.net>
Paul Halliday <dp@penix.org> writes:
: I just connected my gps (garmin gps III plus) to my serial port
: and realized that simply cat'ing cua0 displays date/time/position of the
: unit. (neato). Anyway, how accurate would it be to use the time from this
: output for ntp as opposed to my current setup using ntp servers.
Generally the output time from these receivers via the serial port
isn't very good from a precise time keeping point of view. There's
about 10ms of variation in the reported time, which makes them very
very noisy for the sort of work that ntp does. For a local network,
it shouldn't be too bad, but expect to see a lot of strange things
happen because the error can be so large.
Warner
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