Multiple approximations can often be very accurate when averaged. We had an NMR machine on the 1st floor ( UK so twelve feet from the ground) that was fine until they built a four lane highway in the air outside. Lorries carrying steel do have cause problems to sensitive magnets. However we found that if we ran the tests multiple times then the random background noise actually diminished and we were getting results that matched those of much more sensitive and expensive equipment.
It might be worth while investigating if the same is true for GPS, I suspect it probably is. Something to do with bell curves in maths. Cheerio John >> So, be cautious before deleting a way that doesn't match your >> gps track, unless you have multiple tracks that confirm the way >> is wrong. > > Multiple tracks with errors only create more ambiguity. There is no > guarantee that having multiple GPS tracks will give you an "accurate > estimate" of the actual location of the road being tracked. It is > possible that all tracks are offset from reality in the same general > direction, rather than being equally distributed, creating an accurate > average value. The only way to confirm that the way is incorrect, is > to use sub-centimetre accuracy professional level GPS equipment, which > is not only out of my reach, but probably most of the people involved > in the OSM project. > _______________________________________________ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca
