[time-nuts] Averaging Location for Position Hold
mail at miguelgoncalves.com
Tue Sep 13 22:08:25 UTC 2011
I discussed this matter with a friend that did some GIS work a few years
back and we both believe that the unit reporting the wrong position might be
doing this because it's only seeing half of the sky (it is near a window
facing SE) while the other one sees the entire sky.
My friend pointed out that Google Maps are used today in navigation systems
and while the software might have some corrections algorithms built in he
believes that the maps should be reasonably accurate.
On 13 September 2011 22:25, David VanHorn <D.VanHorn at elec-solutions.com>wrote:
> Also, can you really trust Google Earth as an authoritative source?
> I'm not sure. An interesting test would be to go find a USGS
> benchmark or a section marker near you then enter it's location into
> Google. See if Google hits the marker.
> For what it's worth, my Thunderbolts here did a 48 hour survey, and the
> position they report, fed into google earth, hits the north side of the 3' x
> 3' skylight they are in.
> Roughly 18" error.
> Maybe luck, but they both report almost identical positions. I'm north of
> Denver, so I'm a bit off the spherical average.
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