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View Full Version : Highest resolution satellite imaging?



Lunnalkann
2004-Jan-23, 03:21 PM
While looking at something else, I found this quote:


QuickBird was lofted in October 2001 and is billed as the world's highest resolution commercial imaging satellite. It can see things 2-feet (61-centimeters) across.

The quality it produces is superb, for example this photo of the Eiffel Tower. (http://www.space.com/php/multimedia/imagedisplay/img_display.php?pic=h_eiffel_tower_02.jpg&cap=Digi talGlobe's%20powerful%20QuickBird%20satellite%20is %20cranking%20out%20ultra%20close-up%20imagery%20of%20Earth%20targets.%20As%20exampl e,%20this%20picture%20shows%20the%20Eiffel%20Tower %20in%20Paris,%20France%20--%20taken%20March%2027,%202002--%20and%20demonstrates%20the%20quality%20of%20pictu res%20churned%20out%20by%20the%20high-flying%20satellite.%20Credit:%20DigitalGlobe) If a commercial grade satellite can make this sort of resolution, what would the military grade be like? If it is confidential, how accurate is it roughly?

Amadeus
2004-Jan-23, 03:47 PM
Well I expect it's confidential. But I would not be surprised if the can red a licence plate. I know there's the issue with heat haze and dust but they could get round that with image processing.

I would assume this is done by taking several pictures in quick succesion, laying them on top of each other and using only the pixels that appear in each frame.

wedgebert
2004-Jan-23, 04:58 PM
Well I expect it's confidential. But I would not be surprised if the can red a licence plate. I know there's the issue with heat haze and dust but they could get round that with image processing.

I would assume this is done by taking several pictures in quick succesion, laying them on top of each other and using only the pixels that appear in each frame.

I doubt even our military satellites can read license plates yet. In order to read a plate, you'd have to be able to resolve objects about 2-3 cm across (width of the lines in the letters).

In fact, you'd most likely need a much higher resolution to account for the poor viewing angle. License plates are almost parellel with the viewing angle of the satellite, so it's going to look distorted, if it's even visible.

Squink
2004-Jan-23, 08:26 PM
There's a big long thread on spy satellite optics, with many links, over here (http://boards.straightdope.com/sdmb/showthread.php?t=153581&highlight=satellite+resolu tion).
The size of the KH-11 mirror, and its distance from the surface, the best theoretical resolution would be about 2" per pixel. That doesn't take into account things like atmospheric turbulance. On the other hand it also doesn't take into account the possibility that the CIA has upgraded a few satellites with artificial aperture technology.