OpenStreetMap
I've downloaded some Digital Orthphoto Quadrangles from seamless.usgs.gov,
which are .3m resolution rectified aerial color photos,
all in the public domain, and quite useful for mapping,
e.g. reviewing the Tiger-based data around here.
They just ask for attribution/recognition,
so here it is: I will improve/review the Central San Diego
part of OSM using the DOQs provided by the US Geological Service.
Thanks, Feds.
Discussion
Comment from Biogenesis_ on 27 June 2009 at 01:12
Attribution probably means that they require you to add a source=US_Geological_Service to any node/ways added or modified based on the information contained in the imagery they provide.
Comment from Vincent Broman on 27 June 2009 at 03:46
Here is the explanation on their web site....
The data from The National Map Seamless Server is public domain. There are no restrictions on data downloaded We request that the following statement be used when citing, copying, or reprinting data:
"Data available from U.S. Geological Survey, EROS Data Center, Sioux Falls, SD."
A request is not a requirement. I won't be citing, copying, or reprinting
the photos, at most just creating a derivative work.
I think my notice here is sufficient and reasonable.
Comment from Biogenesis_ on 27 June 2009 at 08:55
Fair enough, given that it's public domain as opposed to some form of nonrestrictive license. What I quoted above though is the standard request of OSM when entering any data though.