Sparked by Editor B’s remarking upon my Google Maps and Indiana post of yestereve, a denizen of the Hoosier state drops a line:
It is interesting how the term “satellite imagery” is thrown around fairly casually these days. Google would lead us to believe that all their imagery is satellite imagery. In fact, the Indiana images are part of a statewide aerial photography project that was undertaken by the U.S. Department of Agriculture in 2003. Indiana looks different at small scales because this aerial photography is much different data than the majority of the course-scale satellite imagery displayed on Google Maps. Note the difference in resolution and color when you look close at an area near the state line.
The Illinois image probably has a 30-meter spatial resolution (each pixel is 30m x 30m), whereas the Indiana imagery has a 1-meter spatial resolution. This has a huge impact on the ability to view detail at large scale and the overall color of the image at small scale.
Note also that some areas of Indiana and other states have some areas of even higher resolution imagery.
I suspect much of this higher-resolution data is aerial photography–not that it matters much to the casual user.
You can view the same imagery for Indiana which runs on IU’s Research Database Complex.
Simply zoom in near Bloomington and turn on the 2003 Aerials (also need to turn off the 1998-1999 aerials).
Hope this clears things up a little.
The correspondent has been invited to provide self-attribution in the comments; if he does not, it’s due to privacy concerns.