rgl at ruilopes.com
Sun Sep 28 10:35:41 UTC 2008
Eric Muller wrote:
> Jesper Norgaard Welen wrote:
>> Of course you would need the Latitude and Longitude of the airport codes
>> to do what *you* mentioned, but I assume that would be trivial?
> The UN/LOCODE (CODE FOR TRADE AND TRANSPORT LOCATIONS) database has
> coordinates for many locations, and airport codes for airports.
I've tried to use the geonames.org database, but some airports seem to
have wrong coordinates (when seen in google maps). I'll try to compare
it with LOCODE db.
> Generating the list for all the airports should be relatively trivial
> if you put the map in spatially-enabled database such as PostGIS.
> Something like
> SELECT unlocode.code, tz.tzid
> FROM unlocode, tz
> WHERE ST_within (tz.geom, unlocode.location)
> AND unlocode.class = airport;
> assuming that unlocode is a table for the UN/LOCODE database and the
> coordinates have been turned into point geometries (of course, the SQL
> above is just the idea)
the tz table is from your shapefile at http://efele.net/maps/tz/world/ ?
> The main difficulty would be to have a good enough map, so that the
> UN/LOCODE coordinates do not fall in water. May be a bit of buffering
> around the point and an intersection with tz polygons would do the trick.
By map you mean the TZ map from your shapefile?
Can you elaborate a bit about the buffering and intersection? (I'm
starting to enter into the GIS world, so I don't yet known the lingo).
More information about the tz