On Thu, Nov 17, 2011 at 4:47 PM, donglai <[email protected]> wrote: > Hi all: > > I'm thinking to build the lane model for OSM using machine learning > techniques. How can I get multiple gpx files from osm database for certain > roads?
the GPX tracks in the OSM database are not explicitly related to the roads - it is a completely different dataset in that regard. to download tracks for an area of interest, there is the "trackpoints" API call [1]. however, for bulk downloading large areas there is no good method (yet). perhaps using the trackpoints API call near some major intersections would yield the data you need? cheers, matt [1] http://wiki.openstreetmap.org/wiki/API_v0.6#Retrieving_GPS_points > Thanks in advance for any advice or feedback. > Best > D. > > Below are my half-baked ideas: > > 1) Motivation: > > a) According to Sebastian Thrun, in order to build the autonomous driving > car, they push google map to 15cm accuracy with lane models !!! (I guess > they do it in an expensive way, maybe only for part of CA to test their car) > http://www.youtube.com/watch?v=bp9KBrH8H04 > > b) Also, several OSM members have already proposed the lane tag for the map. > However, it'll be a pain for our dear brave volunteers to track and mark the > lane they were in. > > > 2) One possible way out: > a) the bottleneck is that gpx files uploaded by users are often too noisy to > figure out the lane assignment. But we have the "turn constraint" (change to > inner/outer lane before turning left/right) and relative geometry shape of > the route. > b) Given multiple gpx files for one road segment, we can have a robust > estimation of the lane model using machine learning techniques. > c) Also, such technique may be useful for map refinement instead of asking > users to correct by their own where the accuracy is in meters. > > _______________________________________________ > dev mailing list > [email protected] > http://lists.openstreetmap.org/listinfo/dev > > _______________________________________________ dev mailing list [email protected] http://lists.openstreetmap.org/listinfo/dev
