• agitatedpotato@lemmy.dbzer0.com
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    1 year ago

    I bet the jammers were unsophisticated enough you could just program the GPS to continue moving in the direction where the over the air noise levels kept increasing.

    • circuscritic@lemmy.ca
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      1 year ago

      For all the legitimate criticisms of Russian military, their EW and Counter-EW capabilities are actually world class. Which is why it is a big deal when they’re destroyed, or captured.

    • Longpork_afficianado@lemmy.nz
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      1 year ago

      Depending on the range at which the signals start to become jammed, it could be possible to navigate solely by IMU for the final leg also.

      • Syldon@lemmy.one
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        1 year ago

        This is exactly how it was done. The missile used can be set to measurement units and only needs GPS occasionally for precision. It was not relying on GPS totally. Ukraine are not going to waste an expensive GPS guided missile when they know it is going to be blocked near the target.

        • Longpork_afficianado@lemmy.nz
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          1 year ago

          I’m not sure I follow you. If the missile is using gps for guidance(during at least part of it’s flight), then it is by definition a gps quided rocket is it not?

          Also, gps quidance isnt terribly expensive. I use industrial grade units which go for about 3kusd and provide sub-metre accuracy in highly gnss denied enviroments. Lower grade ~3m accuracy units go for around a hundred dollars, and would be completely sufficient for hitting a target the size of a truck.

          • Syldon@lemmy.one
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            1 year ago

            Yes it was (reputedly) a GPS weapon that took out the jammer. But it was one that had a back up option for when the GPS was being jammed. It did not just rely on one guidance system. I do not in any way shape or form profess to be an expert on these things. I am going from the opinions of those who are looking closely at stuff like this. Denys Davydov gives his opinion on what was used and why.

            None of these missiles are cheap. Each one fired has a command structure behind it to make it an effective use of the hardware. Remembering Ukraine is under pressure from the US regarding good use of the funds being sent over. The rocket mentioned in the video was GMLRS Munitions. There are much more expensive options that could have been used, but they would not have been an effective use of the funds. This missile has an estimated cost of $225k. There is more to the missile than a single guidance system.

    • brianorca@lemmy.world
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      1 year ago

      The bombs were probably using the encrypted military GPS frequencies that are more resistant to jamming.

      • circuscritic@lemmy.ca
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        1 year ago

        Encryption isn’t really a factor with this type of satellite navigation jamming, at least as far as I’m aware.

        Frequency hopping however can be a used as a RF jamming countermeasure, but I’m not sure if that is really for satellite navigation systems.

        The frequencies all satnav systems work on are also very specific and known. I would assume that any satnav jammers just jam all RF used by all GNSS constellations at once, but maybe they open up certain bands to allow for their own guided munitions at pre-scheduled times.

      • SuperJetShoes@lemmy.world
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        1 year ago

        As another commenter said, I don’t think cryptography is the main problem.

        You’ve got to be able to modulate some numbers out of the radio signal first before you need to be concerned if it’s encrypted or not.

        GPS signals from power conserving satellites are so weak that I’d imagine that overwhelming them with noise on all frequencies would be the easy answer. (Although there’s a Big Brain hyper-cunning answer to that…).

        • brianorca@lemmy.world
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          1 year ago

          Some GPS jammers are known to transmit, instead of noise, a bad signal which creates an offset in the timing to calculate a false position. But with encrypted military GPS, that’s not as effective.

          • circuscritic@lemmy.ca
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            1 year ago

            I don’t think PGMs with M-Code GPS capabilities are being provided to Ukraine, but that is definitely something well outside of my casual knowledge base, so I’m open to being corrected.