[Openstreetmap] Satellite cost/benefit
f_mohr at yahoo.de
Sun Feb 20 12:57:16 GMT 2005
Jo Walsh wrote:
> > GPS collection
> could be 'sexy' in the right context: e.g. cyclist groups like the
> Tower Hamlets Wheelers of the Camden CC could love this; we could
> introduce a street scoreboard for cycle couriers; etc.
The map data (at least new data) for bbbike
is collected that way.
> > using out of copyright data
> > ---------------------------
> > benefits: free, easy to obtain
> > costs: out of date data
Who long are maps copyrighted?
- I had a look at a german roadmap (1:500000) from 1955
-> most "autobahn"-sections are missing.
-> major roads have changed
- I compared the GPS data of my New-Years holidays with a
streetmap of Cologne from 1960 and a current streetmap
-> streets were renamed
-> inner city streets changed, some are now pedestian areas
-> access roads to bridges changed
-> most of the cathedral/station/rhine area changed
- Even if I compare a 1997 streetmap atlas (1:20000) with
my daily way to work
-> 2 motorway interchanges had been modified
-> a street crosses the office building i work in
-> some industrial areas are missing or have changed
-> several intersection changed to traffic circles
-> in my (small) hometown, 2 development areas that
started that time are missing
> Schuyler's played with the
> douglas-peucker line simplication technique and got interesting if not
> totally convincing results. even a GPS layer would be a place to start
I'm still working on a algorithm to do some track-bundle averaging.
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