Am 28.08.2014 um 21:48 schrieb Peter Barth: > Hi, > > Christoph Hormann schrieb: >> Great to see the waterways are getting some attention. Does this only >> analyze SRTM elevations at start and end point or are the surrounding >> waterways considered? > > currently start and end point only. I have code to do more, but for the > easy tasks that was not necessary as I have a fairly high number of true > positives. > >> If a waterway meets another waterway at one side >> but is unconnected at the other for example this is usually a strong >> indicator for the direction independent of the elevations data (which >> is only helpful usually in mountain areas). > > Actually I found many streams where start and end point are not > connected to anything at all. However, for those cases (not mountain > areas) the aerials didn't help neither in most cases ;) But as I'd like > to get a mostly complete waternetwork for another project, I'm planning > on extending the challenge at some point. > >> In terms of usability it would of course be good if you could see the >> direction in MapRoulette so you can verify the data without actually >> loading it in the editor. > > Serge suggested this, too. But I did never understand what the direction > would tell the user? Does it denote the current way's direction or the > supposed correct direction? How would the user know? And my biggest > concern is, that in many cases you need aerial anyway to be really sure. > > Anyways, would be happy to add this, once I got, how this should be done > :) You may add arrows in both directions, color-coded for "assumed" and "current" (and explained in the challenge description on the top right)
regards Peter _______________________________________________ talk mailing list [email protected] https://lists.openstreetmap.org/listinfo/talk
