At 02:51 AM 10/9/2007, you wrote: >Dave Clark wrote: > >Very very roughly, AIUI: the aerial imagery providers give a right to >their customers (Yahoo included) to create derivative vector works. >Yahoo has sublicensed this right to us. Their lawyers have checked >this out and they're happy with it - and the OSM/Yahoo agreement has >had sufficient publicity that, if the imagery providers had problems, >you can bet we'd have heard about them by now.
Thanks for the info on the Yahoo images. I figured that there must have been a good reason for the recommendation to appear on the Potlatch page. >To answer the original question, though, trust your GPS over the >imagery. The imagery may not always be rectified, whereas as long as >your GPS has produced a good-quality track - i.e. no "concrete >canyon" distortions - it should always be accurate. I very much disagree with this idea. Existing maps and images are not likely to be consistently off by a significant amount. If they are, just find another source to make a comparison to. I find it hard to believe that anyone who has used a GPS receiver much would think that they are consistently accurate. I have never seen a GPS *not* produce errors. There are any number of reasons for the inaccuracy of a GPS receiver including sun spot activity, cloud cover, limited sky view and low batteries, just to name a few. Multipath is just one of many, many sources of uncorrectable error. _______________________________________________ newbies mailing list [email protected] http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/newbies
