On Fri, 30 Jul 2010 21:27:43 John F. Eldredge wrote: > I have to admit that I am bad about not bothering to enter a comment, > particularly if all I have been doing is fixing the alignment of streets to > better conform to the Yahoo aerial view.
<snip> Don't forget, the Yahoo! aerials might not be exactly aligned in all areas. I have found here in Korea the aerials are a little off in some places, but correct in others. I generally move the aerial layer until some obvious feature lines up with a GPS trace (either my own, or downloaded), then I start tracing other features from the aerials. For example, in my town the aerials are off by about 10m south and 8m east. I have to slide the layer up and left to align to the GPS. Of course, it's true the GPS traces are also off by 5, 10, or more metres, but you can overcome this by taking the average of many traces along the same road. In my case, the obvious aerial feature I use is an oval running track. I have collected several GPS traces of this track, and they all agree with each other. I apologise if you silently inferred that "of course I align the aerials first before I start fixing streets", but maybe this is new information for some people. Best wishes, Andrew PS I always try and put some changeset comment in, but I had/have no idea if anyone reads them. I also make mistakes such as not changing the comment if I do two changesets in a row, or sometimes leaving the comment blank. Oh well. _______________________________________________ talk mailing list [email protected] http://lists.openstreetmap.org/listinfo/talk
