Orbital surveillance satellites now exceed 1 inch resolution.

The most recent public estimates of spy satellite resolution capabilities give them as about 10 centimeters, 4 inches. However, it is widely known that the most advanced astronomical space observatories lag what is currently available for military and intelligence satellites. The Hubble Space Telescope for example was derived from early technology surveillance satellites.
Then since the James Webb Space Telescope has a segmented 6.5 diameter mirror, very likely this at least is available now for surveillance satellites.
I discussed the capabilities for such a mirror for space-borne imaging in the post to sci.astro linked below. At 300 km altitude it would have better than 3 cm resolution, about an inch. Spy satellites frequently have elliptical orbits that can bring their altitude to half this at closest approach, so their max resolution will be perhaps half this, 1.5 cm to 1 cm.
The James Webb Space Telescope is however an infrared telescope. The question I had was whether the mirror smoothness tolerances required at visible wavelengths were available using the beryllium material used in the segmented mirror of the James Webb.

From this web site we may conclude that this is indeed possible:

ESO Press Photos 34a-b/97
12 December 1997.
First M2-Unit and Beryllium Mirror Delivered to ESO.
www.eso.org...

The ESO's Very Large Telescope (VLT) uses 1.2 meter beryllium mirrors for its secondaries. This requires visible wavelength smoothness since the VLT will operate at both visible and infrared wavelengths. The James Webb hexagonal mirrors are 1.3 meters in diameter. So we may conclude beryllium mirrors of this size could be polished to the smoothness required for visible light observations.

This question was raised by me in regards to astronomical planetary imaging: how soon could this be adapted to space missions to the planets? The James Webb telescope is a 4 billion dollar mission. However, a large part of this cost probably has to do with the fact of the high reliability required for this mission that has to operate far away from the Earth and therefore can not be serviced by human missions, and because of the fact the entire spacecraft's structure has to be optimized to keep the cryogenic temperatures required for the highly sensitive infrared observations.
Reductions in cost for similar sized planetary missions can be fueled by commercial imaging interests. It is clear there there would be commercial uses for Earth imaging at 1 inch resolution, though this would raise clear privacy concerns. The technology for producing such large foldable space mirrors has been patented so can now be licensed by commercial imaging concerns:

Deployable space-based telescope.
Abstract
A large aperture light-weight space borne telescope is provided which may be launched by a relatively small launch vehicle. A 6 to 8 meter primary telescope composed of, e.g., 30 segments arranged in two concentric rings is provided. Supplemental outer mirror segments are stowed behind and substantially perpendicular to the main mirror which is usable in the absence of supplemental mirror deployment. Deployment of outer mirrors segments provides a large aperture telescope with a large field of view. Other deployable components include a secondary mirror, a bus, deployable with respect to the optics portion, and one or more sun shade sheets or panels.
Patent number: 5898529
Filing date: Jun 20, 1997
Issue date: Apr 27, 1999
Inventors: Wallace W. Meyer, Robert A. Woodruff
Assignee: Ball Aerospace & Technologies, Inc.
www.google.com...

Bob Clark

********************************************************
From: "Robert Clark"
Date: 10 Jan 2007 09:12:09 -0800
Subject: We will soon be able to resolve Mars microbes from orbit. ;-)
groups.google.com...

Impressive, amazing. We need this technology @ Mars now!

Wonder how clear these "inches" are?

It is pretty certain that we have the technical capability now for
producing such large segmented mirrors for visible light imaging.
The question is of the cost. I was arguing that commercial
satellite interests investing in this would lower the cost for the
production of satellites for planetary imaging. There are
privacy concerns, but there would be some beneficial societal effects
as well.
We can imagine that such satellites are orbited in sufficient number
to provide world-wide round-the-clock coverage to be able to
distinguish faces and license plates. You could use "light
intensification" or infrared viewing devices for imaging at night.
This though raises the spectre of "Big Brother" in outer space.
However, an advantage which be the great reduction in crime this
would produce. For any crime committed you could trace back in the
images the houses that the perpetrators orginated from.
This would be preventive in the sense the perpetrators would know
they would soon be tracked and identified. However, in the case of
terrorists in many cases they wouldn't care that they would be caught
or identified. But this could be preventive if certain suspected
terrorists could be put under round-the-clock surveillance. Then
certain illegal activities or purchases could be identified beforehand
to stop the terrorist acts before they take place. You could also do
spectroscopy from space so that production and/or transport of
explosives would automatically set up a red flag to alert to the
possibility of terrorism.
The privacy concerns would be magnified even further by ongoing
research on imaging methods that can see through clothing and even
walls, if these methods were placed on satellites:

First Image from Revolutionary T-ray Camera; Sees through Fog,
Clothing and into Deep Space.
By Robert Roy Britt
Senior Science Writer
posted: 01:30 pm ET
11 February 2003
www.space.com...

Tuesday, February 20, 2007
T-Rays Advance Toward Airport Screening.
A new laser design helps create usable terahertz radiation, which
penetrates common materials but doesn't harm tissue.
By Neil Savage
"Zhang founded a company, Zomega Terahertz that makes a laptop-size T-
ray detector that can be attached to a flying drone for remote
detection of chemical and biological substances. While the trillionths
of a watt produced by the infrared laser in the device is fine for
spectroscopic analysis of air samples, it's not adequate for imaging,
and the laser technology is unlikely to improve enough to be used in
airport security, Zhang says. He believes that quantum cascade lasers
are the future of T-ray detection systems: "They will be the final
winner in the market."
www.technologyreview.com...

The question: would you favor the use of such satellites if it would
virtually eliminate crime and terrorism?
How about if the imaging was only available to government agencies
and it required a court order to initiate preventive prior
surveillance or the tracing back in video of an individuals movements
in time?


Bob Clark