[OSM-talk] redundancy problem

[Andreas Volz]

Am Tue, 25 Sep 2007 07:56:40 +0200 schrieb Andreas Winckler:

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> Hi all,
> 
> this is a question from german discussion group:
> 
> There's a recycling company which is willing to provide GPS-tracks to
> OSM. They have 4 or 5 trucks to collect chemicals and old batteries
> on a daily basis. The trucks are equipped with telematics and will
> drive all over south eastern Germany.
> 
> Now we're discussing the problem that the trucks will generate
> massivly redundant tracks, especially nearby their home base.
> 
> As far as I know there are bicycle couriers in London which also
> provide GPS-tracks. They should have the same problem.
> 
> Is track redundancy a problem? If so, is there already a solution for
> it?

Hi,

collect the tracks for some time before uploading and filter them with
gpsbabel. I had success with this script:


#!/bin/sh

GPXNAME=`ls $1 | sed s:.gpx::`

gpsbabel -i gpx -f $1 -x position,distance=5m -o gpx -F ${GPXNAME}_filtered.gpx


And as I remember it should be possible with gpsbabel to delete all gps points
in the radius of a gps position (e.g. your home).

An improvement would be to download existing gps points from the server before 
filtering them with gpsbabel. Then upload only the new gps points and ignore the 
yet existing. This would minimize the redundancy.

Has someone yet started such a tool?

regards
Andreas