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

[Franc Carter]

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.

cheers

On 9/17/07, Franc Carter <franc.carter at gmail.com> wrote:
>
> Two places that I saw on the imagery last night, was a nice round paved
> circle in
> Hyde Park and an intersection of paths in the Domain - I'd expect both of
> these
> points would have fairly good accuracy. The other place that I just thought
> of is
> Darling Harbour - it should have some easily identifiable points.
>
> I can't think of any points that in the real centre, unless I can find a
> building where
> there is public roof access.
>
> I'm 'hoping' that points on the outskirts will be enough that aligning the
> Yahoo Imagery
> to them will result in the points derived from the are 'at least better'
>
> cheers
>
> On 9/17/07, Ian Sergeant < isergean at hih.com.au> wrote:
> > "Franc Carter" < franc.carter at gmail.com> wrote on 17/09/2007 10:09:34 AM:
> >
> > > I agree the city is reasonably complete, there are several small
> > > (tiny) lanes missing,
> > > especially around the eastern side.
> >
> > Some of these are very hard to get right from Yahoo Imagery.  I just added
> > all
> > the Phillip Lane stuff around the back of Phillip St, and Farrar Place on
> > Young Street.
> >
> > These were previously drawn as through ways, when there are bollards and
> > various one way arrangements.
> >
> > > It's the accuracy that seems to be a bit out in
> > > some places, i.e streets not being parallel and such. So 'something'
> > > is out because the traces are bad it's difficult to decide which are the
> > good ones
> > > and hence fix it become a consistent accure whole.
> >
> > > I was thinking of getting some more accurate points from GPS averaging
> > and then
> > > working from them and the Yahoo Imagery.
> >
> > It can't hurt..  There are parts of the city where GPS traces are never
> > going to work.
> >
> > > If you have some accurate points, I think it would be great to put
> > > them in to OSM
> > > and label them in some way.
> >
> > It is a shame that the GPX upload only seems to remember track points and
> > not waypoints.
> >
> > I have labelled all the ways derived from GPS point averaging as
> > source=survey.
> >
> > Are there any really accurate locations that you can find on the Yahoo
> > Imagery?  I could get good references for those and put them on the Sydney
> > Wiki page as a base for CBD mapping?
> >
> > Ian.
> >
> >
>
>
>
> --
> Franc


-- 
Franc