[time-nuts] Setting Rubidium to match GPS source
bruce.griffiths at xtra.co.nz
Fri Sep 28 20:26:43 EDT 2007
SAIDJACK at aol.com wrote:
> In a message dated 9/28/2007 16:02:30 Pacific Daylight Time,
> bruce.griffiths at xtra.co.nz writes:
> Surely a height error of 2m leads to a timing error of about 6.6ns for a
> particular SV when that SV is directly overhead.
> When the SV isnt directly overhead a 2m error in height contributes less
> error than this to the slant range and the corresponding propagation
> delay error from the SV to the antenna will be less than 6.6ns.
> Hi Bruce,
> it's not 2m, it's about +-2m = 4m :)
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Somewhat confusing when one specifies the maximum height error as +-2m
and then quotes the corresponding propagation delay error as 12ns which
is actually the total range of the maximum corresponding slant range
propagation delay error. Error usually denotes the difference between
measured/calculated value and the actual value. When the height error
bounds are symmetric about the actual height as implied by the -+2m
spec, the corresponding propagation delay error bounds will also be
symmetric about the actual propagation delay, so in this case quoting
the propagation delay error range perhaps imparts a pessimistic
impression of the magnitude of this error.
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