diff options
| -rw-r--r-- | timebase.c | 8 |
1 files changed, 7 insertions, 1 deletions
@@ -70,7 +70,13 @@ what rollover period we're in, we're utterly hosed. Furthermore, if it's not accurate to within a second and only NMEA devices are reporting, we don't know what century it is! -Therefore, we must assume the system clock is reliable. +Therefore, we must assume the system clock is reliable to within a second. + +However, none of these caveats affect the usefulness of PPS, which +tells us top of second to 50ns accuracy and can be made to condition a +local NTP instance that does *not* rely on the system clock. The +combination of PPS with NTP time should be reliable regardless of +what the local system clock gets up to. This file is Copyright (c) 2010 by the GPSD project BSD terms apply: see the file COPYING in the distribution root for details. |