"Robert Casey" wrote in message
...
Jack Harrison wrote:
Resolution of 50 cms per pixel for Mars! Excellent.

The highest resolution routinely available from NOAA satellites
orbiting Earth is 250 metres per pixel (Modis). It would be nice to
see pictures of Earth to resolution of 50 cms per pixel. Landsat?
But I can't find anything on internet.


Spysats are at least this good if not better. Spysats the
size of Hubble must be quite good. The atmosphere astronomers
complain about blurring their astro pictures probably don't
bother the spy sat guys, as sunlight on the items of interest
on the ground allow quick exposure settings in the cameras of
the spy sats. Before the atmosphere wiggles. Even at
night adaptive optics should be able to clean up the
atmospheric wiggles enough to see stuff. Someone who
knows the physics of optics for telescopes can probably make
a very good guess of the resolution one could get with say
a 1 meter reflector spy telescope. But the other guys will
just do their dirty work inside buildings or underground...

Rumor has it at certain times specified spy satilites were in such a
position to where they only looked out into space. The operators snapped
what they thought were a few cool Pic's that eventually were shown to a few
select members of the astronomy community. "Shazam Batman", the rest is
history.

Needless to say Hubble was designed/built by a different group, with a few
hints here/there, than built the spy satellites. This is why the original
mirror was flawed.
Ralph Nesbitt