• skillissuer@discuss.tchncs.de
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    1 year ago

    you can still jam common control channels in this case, like with any other FPV drones

    you can’t jam everything, because it would consume enormous power and system would be massively complex. my bet is that they have used some band that was not commonly used, and so, not jammed yet. maybe it’s a band that is normally used by some obsolete protocol or service, that got commandeered for use by military

    • skillissuer@discuss.tchncs.de
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      1 year ago

      all it takes is making FPV drone communication modules from scratch, it’s custom job but also known technology. maybe even some components were already commercially available

    • skillissuer@discuss.tchncs.de
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      1 year ago

      there are much niftier techniques, but this is probably the simplest one and i don’t think anything more advanced is needed in case of disposable FPV drone

    • Excrubulent@slrpnk.net
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      1 year ago

      Ah, okay, so it’s about making sure the signal can still get through. That’s not an easy problem to solve because the video and the control signals run on different frequencies and you need both of them to work.

      I have more speculation about how they might’ve done it but I’ll fight my tendency to infodump just this once.

    • bouh@lemmy.world
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      1 year ago

      I’m pretty sure “heavily jammed” means most radio frequencies will be jammed.

      But the drone can enter autonomous mode when it happens and direct itself with lidar, gyroscopes and cameras I imagine.

      You can also direct it with the jamming signal itself if that’s what you’re looking for.

      • skillissuer@discuss.tchncs.de
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        1 year ago

        if you expect drones to be used, it makes sense to jam 2.4ghz, 5ghz (communication with drone) and 1.6 ghz (gps signal), maybe some more obscure bands like 900mhz and 3.2ghz (communication with drone) but if you make custom drone that uses, say, 7ghz frequency for communication, that’s outside of normal bands and it’s most likely not jammed because there’s no point if it was never used. just filter everything else out and you’re good to go. jamming only thin bands instead of blanketing everything makes jamming effective over much larger area with the same power. you can even make drone use some band that’s used by, for example, enemy’s radar that’s currently not in area, so that band is not jammed by EW device but also not jammed by radar

        But the drone can enter autonomous mode when it happens and direct itself with lidar, gyroscopes and cameras I imagine.

        and how it’s guided? as in, how it’s communicated with operator? because it’s happening here. laser in free space would probably require another drone with line of sight to the first one, as a repeater, and this one also needs to be not jammed, otherwise you need line of sight from drone to operator and this would be pretty hard over distances drones are used now

        anti-radiation drone (like anti-radiation missile) would be pretty nice idea but this one is clearly guided manually, like every other FPV drone. it would also be much bigger (needs some 15x15cm panel with antennas as seeker at minimum and some circuitry for extracting direction from signal)

        • bouh@lemmy.world
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          1 year ago

          Russians are more stupid than I thought then. Jamming commercial bandwidth only is like making armours against commercial weapons only. It’s plain stupid.

        • bouh@lemmy.world
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          1 year ago

          For communication you can command it before it get jammed. Automatic mode could either have a target already or find one alone (although this one might be risky).

          If you can designate the target while the drone is controlled, then it can direct itself with its own sensors like a missile.

          • skillissuer@discuss.tchncs.de
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            1 year ago

            how do you navigate drone in such case? good inertial navigation is expensive and not precise enough unaugmented. GPS will be jammed. TERCOM? i haven’t heard of it being used for cheap drones. what you’re talking about is basically how javelin tracks a target, but this uses some hefty image recognition and is harder than you think

            • bouh@lemmy.world
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              1 year ago

              Well, I thought it was something that deserved a news you know.

              And I’m pretty sure you can have very accurate inertial positioning, and other sensors can help. At least for a short time.

      • skillissuer@discuss.tchncs.de
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        1 year ago

        I’m pretty sure “heavily jammed” means most radio frequencies will be jammed.

        Why arent Russians jamming everything? Are they stupid?

        if you attempt to do this, you get three pretty big problems.

        1. you want to jam only the enemy’s frequencies. if you jam everything, you are denying yourself communications, both civilian like gsm or wifi and whatever specialized devices you might have, and more importantly you are jamming your own radars. things get trickier when you and your enemy are using the same bands, like 2.4/5ghz wifi for drone control. sometimes you don’t see EW used for this exact reason

        2. power spectral density drops massively, decreasing effective range of your jammer. there’s no hard border between jammed/not jammed, there’s a gradual transition instead. when you put lots of radiation in bands that nobody uses, you’re limiting jammer for no reason. it’s better to blare noise only on narrow bands where there’s actual traffic. can you jam everything from 2 to 3.5ghz? sure, but if you really need to jam only 2.4ghz wifi band, then you’re limiting range by about 4x or so, everything else being equal. additionally, things get broadband and it’s bad, because all components need to be broadband, which is harder, heavier, more expensive, or you need to bundle what is effectively several jammers next to each other, some of which would only jam, say, friendly radar

        3. if you’re jamming, you’re jamming for everyone. this also means that you can’t use electronic surveillance on bands that you’re jamming, for example you can’t locate wifi transmitters or drones if you jam wifi bands

        no, “heavily jammed” does not mean “all bands are jammed” as evidenced by fpv drone being controlled by operator and receiving video output, which means that whatever bands they used were open. “heavily jammed” more likely means that common bands like 2.4ghz or gps bands had large spectral power density of whatever they used for jamming (does not have to be white noise and probably wasn’t)