• MeekerThanBeaker@lemmy.world
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    8 months ago

    I’m no GPSjamologist, but if a jammer was running in your car, wouldn’t the signal reach other nearby cars while in traffic or does it do it all within the confines of your automobile?

    • Thorny_Insight@lemm.ee
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      8 months ago

      That is exactly why this is illegal. These things can have a range of up to hundreds of meters and thus you’re affecting other people aswell and not just yourself.

      • Vakbrain@lemmy.dbzer0.com
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        8 months ago

        From the low power models I’ve seen (which are still very much illegal, same as the most powerful ones) only work between 5 to 10 feet at the very most.

        It’s like when the companies place trackers in cars, we have to assume they have the best intentions in mind (it is definitely for the customers security right?!)

        But if we, the customers, block them from tracking us by jamming the GPS signal, they assume we have the worst intentions in mind (surely we are dirty criminals right?!)

        This is why I said it “feels” wrong.

        • abhibeckert@lemmy.world
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          8 months ago

          It doesn’t work like that.

          They broadcast a powerful radio signal on the GPS frequency. You might have to be within 10 feet for it to completely drown out the real GPS frequency, but the waves don’t stop they just spread out and get “thinner” with distance. If it completely blocks the signal at 10 feet, it will severely reduce accuracy further out than that. Likely everyone within line of sight of your car will lose accuracy on their GPS.

          And that would include airplanes, line of sight is a really long distance up above your car. Airplanes use GPS for critical functions including making sure they don’t crash into the ground when they’re flying through clouds / rain / fog so you could potentially cause serious problems. Most likely force the airplane to land in a different city — because they will not land if their altitude equipment isn’t working… yes they have other ways of measuring altitude but all of them are unreliable, which is why they have GPS. You’re taking away one layer of their patchwork system of landing safely and if too many layers are gone then they abandon the landing and fly elsewhere - happened to a friend of mine recently, turned a quick 2 hour flight home into an 18 hour trip.

          • ultracritical@lemmy.world
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            8 months ago

            Not really. Radio power decreases with the square of the distance. So at if “blackout” is at 10 feet then at 100 feet your at 1% of your original power. So realisticly your blocking your GPS signal and partially obstructing signals for 2-3 cars adjacent to you and likely less than that. You wouldn’t be reaching any planes without a lot of power and a big transmitter.

            Planes avionics are more then sufficient to navigate and fly the plane without GPS. And planes will most definitely land without GPS as a.) GPS isn’t the predominant tool for altimetry and b.) a plane has to land or it will crash. GPS is primarily used for navigation of routes and most critically for planning approaches and landings. It enables the tower to send an approach plan directly to a plane. So, really important for packing the skies with planes, but a malfunctioning gps unit isn’t going to stop a plane from landing at its designated airport. May stop one from taking off though. This really only applies to big planes. Small planes don’t always have gps and don’t always land at airports using gps. Still really nice to have so you don’t get lost, though.

            Accurate GPS is a fairly recent luxury as until the 90s it was made inaccurate by design as only the military could access the full radio spectrum, and only recently has the full constellation of current gen sats been fully deployed. Also interestingly commercial gps receivers won’t function beyond 600 mph and/or 60 000 ft to prevent people from using them for missiles. Military ones (in missiles) or if you home brewed it won’t have this restriction though.

            You are right though. Running a jammer is illegal as hell and you can really fuck other people’s day. Especially do not try bring a jammer on a plane. They monitor radio very closely at and around airports. You will be caught and you will be sent to federal “pound me in the ass” prison.

    • Evil_Shrubbery@lemm.ee
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      8 months ago

      This person jamologises GPSs on the regular.

      And yes, I doubt any county would fine you for jamming completely exclusivity (and exactly) only your antenna. It wouldn’t even be detectable.