Couldn't you just make an assumption in most cases? I would think something like 15 - 20ft would be OK. Most roads aren't that close (most!) and I'd think most GPS units are at least that accurate (although I have no experience with GPS in urban environments).
Or even better, a site that would let you upload the track and overlay it on an OSM map with some options that could be changed in realtime. This way you could fine tune your track if you were in different environments with varying levels of GPS accuracy. -Jeremy > -----Original Message----- > From: [email protected] [mailto:talk- > [email protected]] On Behalf Of Ed Avis > Sent: Tuesday, March 10, 2009 10:44 AM > To: [email protected] > Subject: Re: [OSM-talk] Conflating Tracks? > > Daniel A Carleton <daniel.carleton <at> exaptic.com> writes: > > >Are any of you aware of a conflation algorithm that "snaps" GPS tracks > >to the street grid? This could be a useful way to verify existing > >road networks and fill in any gaps. e.g. I go out and ride on city > >streets, overlay my GPS track on the OSM grid, and the algorithm shows > >me where I traveled over unknown segments of road or deviated a > >disproportionate amount. > > To do that you'd ideally want to know the margin of error for the GPS > readings. > My GPS unit (Garmin eTrex Vista HCx) shows an error circle on its > screen > (giving a tighter circle when there is good reception, and a wider one > when the > sky is obscured by tall buildings) but on saving the tracks as GPX this > information is lost. Is there a way to export the track log including > error > circles into a format that the OSM servers recognize? > > (It appears that I could connect the unit to a laptop and record the > tracks with > gpsd, but I would prefer to just carry the unit and recover the track > log > afterwards.) > > -- > Ed Avis <[email protected]> > > > _______________________________________________ > talk mailing list > [email protected] > http://lists.openstreetmap.org/listinfo/talk _______________________________________________ talk mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk
