[Freegis-list] Re: Freemap

[Jan-Oliver Wagner]

On Mon, May 22, 2000 at 02:39:47PM +0000, Jonny Birkelund wrote:
> We cant assure the user that metadata is correct, and IMHO they wont
> be interested in this either, partly because there the gps generates a
> minor error already (shadow from trees, buildings etc) and also the
> government map agency is not accurate either. (horrible on seamaps)

Yes. 'Correctness' is probably a wrong term here. GI have always a number of
uncertainties involved. Besides a trust level, a precision level must
be considered.

> So the questions on accurate maps will be something the governement
> will use to try to kill project like this.

A government can not kill such a project. How should they do it?
Nonetheless we must try to create impressive datasets and
prove that the idea is a good and efficient one. Imagine
how much the 'official' did cost ...

> I think the right thing to do is not to worry too much about accuracy
> today and what today users is think about maps. I couldnt dream abut
> the widespread use of Internet back in 1990 when I first started to
> use this at the University. Mabye there would be something with GPS
> too? Everyone will have a gps in his watch, mobiletelephone, car etc
> in 3-4 years That means a tremendous need for diffent kind of maps. My
> dream is a system which transmit a route-log from their mobilephones
> into the freemapproject or similar with their latest track.log they
> find useful to share with others.

The collection of just 'coordinates' is not all. There need to
be attribute information. Attributes and topology is the most
valuable in GI data sets. Its a pity that a Free GI project
must start with collecting even the coordinates, because
we can not start with the presently available data.

> Slowly we will generate a really big map-database totally free of ugly
> money-hungry governments. 

We must win the governments to contribute their data as Free Data.
The governments are not evil - they just need to be convinced that the
Free Data approach brings more advantages and a higher quality than
a proprietary approach. At the moment governments consult the wrong people
regarding this issue, furthermore the Open Source idea is relatively
new with its professionality.

> The best and fastest way to build a database is getting involved with
> big car-makers who is in really need of maps. (BMW dont have any good
> maps here in Oslo for their cars) A logging system from every car they
> sell here would be wonderful. The same goes for every Taxi. They
> already have GPS in their cars.

Again the attribute problem. The cars don't read the street names where
they are driving :-)

Another way to get digital coordinates is to digitize from aerial or satellite
images. These can be bought and digitized data can be Free Data.
(It is not allowed to digitize from other maps as far as I know)

Jan

-- 
Jan-Oliver Wagner				http://intevation.de/~jan/

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