Even spy planes could not photograph the entire earth. They are higher and faster than normal planes, but still in a different league to satelites. Besides, that cost a ridiculous sum (care to guess what the fuel cost would be to fly around the world thousands of times? Plus wages, wear and tear, crashes, etc). It would decades, even with every spy plane in the world.
quote author=j_lad link=topic=22983.msg475418#msg475418 date=1220452584]
the higher detail photos are taken from planes, and only some by google
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True but the vast expanses of desert still need representation, even if it is low-res. I accept that much of google earth is taken from planes, but only highly populated areas or landmarks. Most of google earth is from companies like JSI (Japan space imaging corperation).