[talk-au] [OSM-talk] city accuracy

Franc Carter franc.carter at gmail.com
Mon Sep 24 10:03:22 BST 2007

I did several passes around the loop that passes by Mrs Macquaries Chair, and
have nudges that road based on the track log - I've been pedantic and tried to
compensate for the side of the road (it's oneway) and the fact that my gps is on
the right side of the car.

So hopefully it's pretty good.

The Yahoo Imagery (in josm) didn't match perfectly, so the Imagery may be warped
a little


On 9/24/07, Ian Sergeant <isergean at hih.com.au> wrote:
> "Franc Carter" <franc.carter at gmail.com> wrote on 22/09/2007 11:54:32 AM:
> > Looks like my gps (tomtom-910) wants to hide info from me ;-(
> > A 3 minute trace log standing still in the domain produced exactly
> > the same lat/lon for every point.
> > Next thing I might try is to drive around as many of the roads on
> > the border of
> > the CBD as feasible to get some boundaries.
> Is the tomtom locking to the road/path?  Are you using the standard tomtom
> software?
> Is it a PDA that will run something that will let you gather the NMEA data,
> to get the accuracy and the location data?
> I gathered a 5 minute sample at 5m accuracy for the Maquarie Obelisk in
> Macquarie Place last week.  I figured it would be a good point to start
> with, since I can put it into OSM as a survey mark.  However, I just
> checked the Yahoo Imagery, and you can't see the obelisk, as it is
> obscured.  I'll upload it into OSM, but its otherwise useless I think.
> There is  still a possibility that the yahoo image is actually a little
> distorted, and can't be normalised just with a nudge.
> I think the waterline along west Circular Quay could be my next target.  I
> can accurately map the waterline, and it should align well with the Yahoo
> imagery in that part of the city.
> Ian.


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