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I remember seeing a photo snapped by a 70s spy satellite that showed a guy lying on a beach and the time on his wristwatch clearly visible. _1970s_. Makes one r

by eps 15y ago

I remember seeing a photo snapped by a 70s spy satellite that showed a guy lying on a beach and the time on his wristwatch clearly visible. _1970s_. Makes one really wonder where things are at now.

arethuza 15y ago
I suspect that was unlikely to have been a satellite shot - even the best resolutions I have seen claimed are still around 5cm to 10cm - which is nowhere near close enough to resolve the time on a wristwatch. http://en.wikipedia.org/wiki/KH-8 http://en.wikipedia.org/wiki/KH-8 http://en.wikipedia.org/wiki/KH-9_Hexagon http://en.wikipedia.org/wiki/KH-9_Hexagon
- iwwr 15y ago
  It should be a relatively simple problem of mechanics and optics. How big would the spy camera have to be to capture that level of detail? Assuming say, a budget of $500mil to 1bn per satellite.
  - projectileboy 15y ago
    ...and atmospheric distortion. That's a much harder problem, although there have been innovations there, as well - some of which have been applied by astronomers to improve the imagery of ground-based telescopes (e.g., digitally processing images based on the observed distortion of a reference image, such as a simple laser from a geosynchronous orbit captured at the same moment).
  - arethuza 15y ago
    Someone does a calculation in this discussion: http://www.natscience.com/Uwe/Forum.aspx/physics/10830/Maximum-resolution-of-spy-satellites http://www.natscience.com/Uwe/Forum.aspx/physics/10830/Maxim... That suggests that the max resolution from 850km (which does appear to be the relevant height) of a 4m as 10cm. So for 1mm resolution, which would be about right to resolve the time an a watch, you'd need at least a 400m mirror, probably much larger. So $1 billion wouldn't be anything like enough. [Apologies to anyone who actually knows about optics.]
  - patrickgzill 15y ago
    ISTR that the SR71 spyplane had large optics that had to loaded by a sled / fork truck and was capable of excellent resolution. See http://www.wvi.com/~sr71webmaster/sr_sensors_pg1.htm http://www.wvi.com/~sr71webmaster/sr_sensors_pg1.htm for example.
- eps 15y ago
  I should really try and find that book the photo was in. It could've been an U2 shot rather than a satellite one, but it certainly was an ultra high-altitude arial shot.
ck2 15y ago
I would assume technology now allows them to cover huge areas, not just resolution. Basically if you are outside, assume you are being recorded. Combine that with warrantless tracking of all cellphone ids and they know who they are looking at. It's just a question of how long they save the data and the fact that agencies don't usually talk to each other so data isn't shared only out of apathy.
akamaka 15y ago
I've seen that photo too, maybe 20 years ago, and although I don't remember where it was anymore, I believe it was a mockup made for a magazine, and not a real satellite photo.

by eps 15y ago

I remember seeing a photo snapped by a 70s spy satellite that showed a guy lying on a beach and the time on his wristwatch clearly visible. _1970s_. Makes one really wonder where things are at now.

arethuza 15y ago

I suspect that was unlikely to have been a satellite shot - even the best resolutions I have seen claimed are still around 5cm to 10cm - which is nowhere near close enough to resolve the time on a wristwatch. http://en.wikipedia.org/wiki/KH-8 http://en.wikipedia.org/wiki/KH-8 http://en.wikipedia.org/wiki/KH-9_Hexagon http://en.wikipedia.org/wiki/KH-9_Hexagon

iwwr 15y ago
It should be a relatively simple problem of mechanics and optics. How big would the spy camera have to be to capture that level of detail? Assuming say, a budget of $500mil to 1bn per satellite.
- projectileboy 15y ago
  ...and atmospheric distortion. That's a much harder problem, although there have been innovations there, as well - some of which have been applied by astronomers to improve the imagery of ground-based telescopes (e.g., digitally processing images based on the observed distortion of a reference image, such as a simple laser from a geosynchronous orbit captured at the same moment).
- arethuza 15y ago
  Someone does a calculation in this discussion: http://www.natscience.com/Uwe/Forum.aspx/physics/10830/Maximum-resolution-of-spy-satellites http://www.natscience.com/Uwe/Forum.aspx/physics/10830/Maxim... That suggests that the max resolution from 850km (which does appear to be the relevant height) of a 4m as 10cm. So for 1mm resolution, which would be about right to resolve the time an a watch, you'd need at least a 400m mirror, probably much larger. So $1 billion wouldn't be anything like enough. [Apologies to anyone who actually knows about optics.]
- patrickgzill 15y ago
  ISTR that the SR71 spyplane had large optics that had to loaded by a sled / fork truck and was capable of excellent resolution. See http://www.wvi.com/~sr71webmaster/sr_sensors_pg1.htm http://www.wvi.com/~sr71webmaster/sr_sensors_pg1.htm for example.
eps 15y ago
I should really try and find that book the photo was in. It could've been an U2 shot rather than a satellite one, but it certainly was an ultra high-altitude arial shot.

ck2 15y ago

I would assume technology now allows them to cover huge areas, not just resolution. Basically if you are outside, assume you are being recorded. Combine that with warrantless tracking of all cellphone ids and they know who they are looking at. It's just a question of how long they save the data and the fact that agencies don't usually talk to each other so data isn't shared only out of apathy.

akamaka 15y ago

I've seen that photo too, maybe 20 years ago, and although I don't remember where it was anymore, I believe it was a mockup made for a magazine, and not a real satellite photo.