Chad tries to address the confusion about a series of high-resolution images appearing in Google Maps and Google Earth. It seems to me that there are two misconceptions: that they’re all satellite images, and that they are real-time (or that real-time, high-resolution satellite imagery could be possible in the future). (Two examples are here and here.)

The images in question are not satellite images, he points out, but rather aerial photography, from a National Geographic flyover of Africa.

In fact, high-resolution imagery is generally taken from airplanes, not satellites. People assume otherwise, but satellites just aren’t that good. Nor — to tackle another misconception — are they that omnipresent. People wonder when we’ll get real-time imagery, or worry about it, but I don’t think it’ll ever happen: a geostationary satellite would be too far away for such imagery. The reason why satellite and aerial imagery is years out of date is because planes and satellites can only cover so much ground at a time: it takes a Katrina-level disaster to mobilize imagery that is only a few days out of date (remember that the pictures need to be processed, not just taken).

(Edited on 3/24 at 1:50 PM to clear up some things; added a sentence in the first paragraph.)