[Talk-us] How accurate is Tiger data vs Yahoo Aerial?

[Alex Mauer]

am12 at bolis.com wrote:
> Any advice or suggestions?  Thanks.

In my area, the Yahoo! photos are wildly inaccurate (shifted east by at 
least 30 meters).

TIGER data is highly variable, getting some roads perfectly correct in 
some places, being completely wrong in others, missing old roads in 
others, and just being out of date in still others.

IMO, a GPS track (or better yet, several)is the only way to fly with 
respect to having a sane base reference.  Once you have that, you can 
align the yahoo images to it and work from there.  Unfortunately, the 
alignment is not retained, and for JOSM, newly downloaded chunks of 
yahoo imagery have to be painstakingly realigned with the existing data, 
which is quite hard to do consistently over large areas.  For this 
reason, I try to only use yahoo data for things that I can't map with a 
GPS (bodies of water primarily)

-Alex Mauer "hawke"