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

Ian Sergeant isergean at hih.com.au
Mon Sep 17 00:31:39 BST 2007

> I have had a look at a few places in Sydney on Yahoo Imagery with
> josm and parts of it
> are out by a fair bit - roads go at inconsistent angles which is the
> giveaway. Obviously
> getting good traces in amongst all those tall buildings is pretty

> So, does this seem reasonable and does anybody have a better way of
> some known good points to work from ?


1. I think most of the CBD areas are fairly complete as far as the streets
go.  There are lots of paths etc that are missing.  Do you notice any
obvious holes?  You should be able to add missing bits by reference to the

2. I have some points for street corners in the CBD.  I have points for
Martin Place intersections, and many other street intersections which I
have got with GPS surveying.  I've generally aligned streets with these
points in the CBD, where I have them.

3. If there is a particular street corner you would like (within a
lunchtime walk of the Quay) I'm happy to get a GPS ref of it for you to
assist.  Street corners work best to avoid the canyoning between street
corners in the city.  I can generally get better than 5m accuracy on the
points, but not always.


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