[GRASS-dev] openstreetmap import

[Hamish]

Hi,

I'm looking at how to import the OpenStreetMap project data into GRASS.
The data is stored as XML; awk or something would parse that into a
GRASS ASCII vector format=standard.

This is a huge dataset, so questions:

cat in GRASS will be limited to int correct? They have their cat defined
as 64bit, although thay have started at node "1" and I doubt they'll
push into 64bit space anytime soon.

It is likely that they'll get up to 10 million points+ though - is
PostGIS more appropriate to use with such a large dataset?

The idea is for them to use GRASS vector modules to clean up the data,
do shortest path routing, etc.

The 1-3 million point memory limit we have (with topology) equates to
the same number of lines? i.e. we can do 1-3 million lines of data
with 50 million vertices under the current code?



> The id links 
>  from nodes to segments
>  from segments to ways
e.g.

<?xml version='1.0' encoding='UTF-8'?>
<osm version='0.3' generator='JOSM'>
  <node id='2222' lat='47.5118' lon='11.100' />
  <node id='3333' lat='48.4014' lon='10.988' />
  <node id='3334' lat='48.4014' lon='10.988'>
    <tag k='name' v='optional name of node' />
  </node>
...
  <segment id='44444' from='2222' to='3333'>
    <tag k='name' v='optional name of segment' />
  </segment>
...
  <way id='299353' timestamp='06-5-5 13:56:42'>
    <seg id='44444' />
    <seg id='44445' />
    <seg id='44446' />
...
    <tag k='name' v='A99' />
    <tag k='motorway' v='highway' />
...
  </way>
</osm>


there is a rather dense osm2shp converter via awk:
 http://article.gmane.org/gmane.comp.gis.openstreetmap/3005



thanks,
Hamish