The GeoEye site photo gallery gives a good idea of the resolution of currently available commercial satellite photos (presumably the company has incentive to show especially good examples of its photography from satellites).
The resolution shown is a lot less than the resolution necessary to read automobile license plates from space (a common 1960s claim of satellite capabilities that was surely an exaggeration for propaganda effect). Much less could a satellite read a notebook in a secret agent's hand, or anything of that kind. I think a lot of members of the general public are confused about the capability of satellite photos, because Google Maps displays aerial photos taken from airplanes under the heading "Satellite," which is always incorrect for the more close-in views (which also are seriously lacking in resolution).
The book Physics for Future Presidents and a course handout for a "physics for future presidents" course at a university
But, in using a 94-inch aperture, they neglect the possibility of flying an optical interferometer, or a deployable mirror. This technology opportunity has probably not been neglected by the powers that be.
Here's a couple of links (they speculate it's a deployable for RF SIGINT, but truth is we don't know):
While I don't know the actual best resolution of satellite imagery but I do know that the U.S. requires commercial satellite imaging to resample to 0.5 meters.
http://www.geoeye.com/CorpSite/gallery/Default.aspx
The resolution shown is a lot less than the resolution necessary to read automobile license plates from space (a common 1960s claim of satellite capabilities that was surely an exaggeration for propaganda effect). Much less could a satellite read a notebook in a secret agent's hand, or anything of that kind. I think a lot of members of the general public are confused about the capability of satellite photos, because Google Maps displays aerial photos taken from airplanes under the heading "Satellite," which is always incorrect for the more close-in views (which also are seriously lacking in resolution).
The book Physics for Future Presidents and a course handout for a "physics for future presidents" course at a university
http://books.google.com/books?id=6DBnS2g-KrQC&pg=PA204&#...
http://personal.carthage.edu/kcrosby/phys100/worksheet-licen...
both go through the steps for calculating the likely resolution of photographs taken by an earth-orbiting satellite.