[time-nuts] More Comments on GPS's ADEV
hmurray at megapathdsl.net
Wed Apr 11 01:20:38 EDT 2007
> FYI -- Note that between 10,000 and 100,000 seconds, the uncalibrated
> diurnal ionosphere signature just about doubles the noise level. The
> GPS broadcast signals contain an approximate ionosphere correction
> that is based on sunspot count, and most receivers follow the GPS
> ICD200 "recipe". However, this "cookbook" correction makes no attempt
> to calibrate for day/night variations, or the variation of the
> ionosphere with latitude. This typically gives rise to a diurnal clock
> signal that is 10-20 nsec in size.
Is there a corresponding position shift between day and night? Which
Could I get better results if I ran the typical survey step twice, once
during the day and again at night, and swapped between them at sunset and
These are my opinions, not necessarily my employer's. I hate spam.
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