sbierwagen 3 hours ago

There's a hard physical limit (the Rayleigh criterion) on the resolution of an optical system by how big the open end is. You won't get "super zoom" capabilities without a satellite the size of a stadium. https://en.wikipedia.org/wiki/KH-11_KENNEN#Resolution_and_gr...

  • alganet 2 hours ago

    What about multiple satellites working to get one image?

    Like the arrays we have on Earth pointing to space, but instead, arrays on space pointing to Earth.

    I know there probably isn't that many KH-style satellites to do it, but would it be possible?

    • GlenTheMachine 2 hours ago

      The alignment has to be better than half a wavelength. That's doable for RF, but for optical telescopes you're talking nanometers. That's not possible (currently or in the foreseeable future) for a spacecraft constellation.

      • sbierwagen 44 minutes ago

        Amusingly enough, there's been some groundwork laid here by gravity wave interferometer constellations: https://en.wikipedia.org/wiki/Laser_Interferometer_Space_Ant...

        You could imagine a deep-infrared mission (longer wavelength, to soften the alignment requirements) launched into deep space (Jupiter+) where both the solar wind density is lower (reducing space weather perturbations) and reduced solar flux would reduce heat loads on the structure, (objects in Jupiter orbit get 3.6% as much light as in Earth orbits) making cooling easier. An interferometer design would also improve resolution. A not-widely advertised feature of the JWST is that, due to the same Rayleigh limits, its far infrared modes have dramatically lower resolution than its near infrared camera. A problem with a 6 meter mirror, less of a problem with a kilometer mirror.

coolspot 2 hours ago

In 2022 Trump declassified this satellite picture showing amazing resolution of current generation: https://media.npr.org/assets/img/2019/09/05/ap_1924315303447...

  • pests 2 hours ago

    By declassified, you mean accidently tweeted a cell phone picture of the image printed out.

    Which is his right, just wanted to add context.

  • rafram 2 hours ago

    That looks about as high-resolution as Google Maps to me. I’m sure the government can do much, much better, but this isn’t a good showcase.

    • defrost 2 hours ago

      Apples to oranges comparison there.

      A great deal of Google Map imagery over urban areas is from relatively low level aerial survey aircraft that run lines over cities in summer.

      The resolution is better and stitched together often provides a better bang for the buck than satellite imagery.

      That said, Trump's image may have been from a sat or from a high altitude spy plane - they'd have ballpark optics but the aircraft would be closer in and more maneuverable .. I'd personally discount whatever Trump had to say about the source and want to hear from a third party military reconnaissance expert.