marcus.bauer at gmail.com
Mon Jun 23 17:46:10 CEST 2008
On Mon, 2008-06-23 at 10:25 +0200, Federico Lorenzi wrote:
> This seems to be really misunderstood. The GPS is the Freerunner can
> get a fix with no help whatsoever, it'll just take longer. This is
> where the AGPS can come in. Download some data off an assistance
> server, and suddenly your time to fix is much less. There have been
> posts to this mailing list about it.
My experience with the Freerunner is ~12 minutes TTFF (time to first
fix) without use of agps and ~4-8 minutes TTFF with agps from
agps.u-blox.com using the software from openmoko.
The Neo1973 (GTA01) had a TTFF without agps assistance of ~2 min.
However, the freerunner shows correct altitude above geoid whereas the
Neo1973 shows only height above WGS-84 ellipsoid. Depending on your
location the difference between WGS-84 and geoid introduces an error
from -102m to +86m towards your real altitude.
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