[Maps-l] Announcement: OSM-streetlist with visualisation on openlayers via kml
Tim Alder
tim.alder at s2002.tu-chemnitz.de
Fri Oct 16 17:50:14 UTC 2009
Hello, I work the last two weeks on scripts that can show special
map-features for an area (bbox) on openlayers:
http://cassini.toolserver.org/~kolossos/streetlist/frames?bbox=13.54,50.95,13.94,51.15
(example Streetlist of Dresden)
With additionally parameters you can see also other objects than
"key=highway", so in the example you can see all rivers near Dresden:
http://cassini.toolserver.org/~kolossos/streetlist/streetinmap3.php?BBOX=13.54,50.95,13.94,51.15&name=*&key=waterway&value=
So you can see that this development goes in the direction of
Query-to-map[1] but is independent from Xapi and Google-API.
It was the question of 80n how fast a PostGIS solution can be, and I'm
really happy with the speed of the script. Database speed is not
everyting, in the past Query-to-map use a long running XSLT process to
transform OSM-XML to KML. Now I don't need this process because PostGIS
has nice functions to transform geometry to KML/GML or SVG. You can look
in the source code of my main scripts [2]. The other scripts are nearly
only simple html/js.
I use the "gis"-database on cassini which is used for our mapnik. I the
moment I use only the table "planet_osm_line". Could I get please some
indexes on columns like "name", "ref" and "highway"? I believe this
would optimize the perfomance further. Could we get for all common keys
[3] a column in the database?
Because I use KML you can use the same script also in GoogleEarth:
http://cassini.toolserver.org/~kolossos/streetlist/Netzwerk-Link-OSM-Map-features.kml
It shows powerlines on Google Earth and reload after 5sec. when you stop
the camera and reloads with your actual BBOX. You can change the URL to
use it for other map-features.
To-Do list:
*Expand it the script to POI, areas and relations. Whats the best way to
do it? A UNION-sql command or a view in the database with all 4 kinds of
objects?
What a look should POIs have?
*Find the bug to get also the highest zoom-levels in Openlayers.
*Prove the database layout to optimize speed. (I have 2 weeks of
postgres experience, who has more? ;-) )
*Using perhaps the caching system like that of Query-to-map.
*Perhaps Openlayers is faster if I would use Mercator-projection inside
the KML.
*Documentation.
*Develop a stable & flexible URL schema to link of the spripts.
*For the street list: Usage Ajax instead of frames to speedup the
script. I the moment I replace the whole map. Who can help?
Use a A-Z register with the first
letter of the name to jump to the right position on the long list.
Who can work with me to make the script so strong, fast and secure that
it can be move to the productive wikimedia server system and be a part
of the map integration in wikipedia. My idea is that wikipedia editors
can add a map to an article and add some parameter to show really the
object of the article in the map. This would be for me thousand times
more fascinating than to show only the pure map. A new kind of
geocoding. But for this we would also need a process to render this
feature on the static map.
Greetings Kolossos
[1] http://wiki.openstreetmap.org/wiki/Query-to-map
[2]http://cassini.toolserver.org/~kolossos/streetlist/index-source.php
http://cassini.toolserver.org/~kolossos/streetlist/street-to-kml2-source.php
[3]http://wiki.openstreetmap.org/wiki/Map_Features
More information about the Maps-l
mailing list