[time-nuts] "GPS once a day issues" ?

Hal Murray hmurray at megapathdsl.net
Mon Oct 20 13:15:28 EDT 2014

kb8tq at n1k.org said:
> The combination of the constellation and the ionosphere are what I believe
> give you the once a day (rather than once per 12 hours) bump.  

There is another layer.  In addition to the "normal" once-a-day type 
differences, the pattern of satellites drifts slowly from day to day.  So 
there is another pattern with a period of something like a month.  If you 
have a marginal setup, for example an indoor antenna, you can see things like 
the holdover times drifting both in time-of-day when they happen and in 
length of holdover as the satellite pattern at dawn/dusk changes.

Of course, at that level of detail, there are lots of other contributions 
like rain that will also show up and may be more important.

These are my opinions.  I hate spam.

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