• DaddleDew@lemmy.world
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    6 hours ago

    You have to be in visual range, or radar range if you have one, which is the horizon plus a bit more depending how high above sea level your are and how tall your target is.

    If you’re on a ship, unless you’re using an advanced radar that bounces signals against the ionosphere or you have a meteorological phenomena called an inversion which can curve your radar energy over the horizon a little bit, your radar horizon is surprisingly short, something around 12 nautical miles give or take. And the sea is big and Iran is quite far.

    This is one big reason why aircraft are used for surveillance at sea. They can go much higher than any ship’s radar antenna mast every could be which significantly expands their radar horizon. They can also scan a huge area relatively quickly as they can travel much faster.

    Because if this fuck up, Iran now has the intel that the French carrier is approaching without even having to send an aircraft out to look for it. If they even still have the ability to do so at this point.

    • gnutrino@programming.dev
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      4 hours ago

      Because if this fuck up, Iran now has the intel that the French carrier is approaching without even having to send an aircraft out to look for it.

      It wasn’t exactly a secret, France publicly announced it was being moved to the eastern med

      • Valmond@lemmy.dbzer0.com
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        5 hours ago

        Or as a duck if they need to move.

        BTW sweden have some cool ship disguises.

        Edit: went looking for it, couldn’t even find a photo.

        Yeah, that’s how good they are.

        • rmuk@feddit.uk
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          11 minutes ago

          The Swedish Navy’s ships do have some bonkers designs, like massive barcodes printed on the side. It’s so that when they get back to port they can scan the navy in.

    • Randomgal@lemmy.ca
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      9 hours ago

      So satellites can see my truck’s plate but an aircraft carrier and it’s escrow fleet are too… Small?

      • astronaut_sloth@mander.xyz
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        8 hours ago

        Sort of. Satellite resources are surprisingly scarce, so a lot are focused where people are, i.e. land. Plus, for the imagery sats that are focused on the ocean, ships are also tiny in a literal ocean of blue. It’s just a spec. While the resolution could be good, have fun looking for that spec. That’s why most countries use signal collection to locate vessels at sea. (I’m over-simplifying a lot, but you get the picture)

        • FauxLiving@lemmy.world
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          8 hours ago

          While the resolution could be good, have fun looking for that spec.

          Seems like an easy but tedious job. Something that a computer can do.

          Object detection algorithms are incredibly fast and can learn to tell the difference between an aircraft carrier and an ocean.

          • astronaut_sloth@mander.xyz
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            7 hours ago

            There are a surprising amount of false positives when using object detection on maritime imagery. While a carrier is a spec, there are a ton of specs in the ocean that can look similar enough. Plus, weather has a huge hand to play. If it were always perfectly clear, then it’s an easier problem, but one cloud can really mess up the detection. Ultimately, ship detection is a difficult problem (not intractable but still hard).

            • FauxLiving@lemmy.world
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              5 hours ago

              False positives are fine, you assign 1, 10, 50, 100 analysts to review hits. You only need to find it once, then the search area becomes incredibly small for each subsequent satellite pass.

              I’m not saying that it is easy, just that you don’t need to have a surface ship within 15 nm in order to see it.

              • EddoWagt@feddit.nl
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                2 hours ago

                I’m not saying that it is easy

                It kind of sounds like you’re saying that. Anyways, there’s a reason submarines exist

      • Iconoclast@feddit.uk
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        7 hours ago

        You still need to know where to point that spy satellite’s camera at. If you take picture that covers hundreds of square kilometers then you don’t have enough resolution to spot the ship but you can’t zoom in much either because you don’t know where to zoom.

        It’s different with buildings because you know where they are.

      • theneverfox@pawb.social
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        7 hours ago

        It’s the ocean. The majority of Earths surface where there’s usually not much going on