Apologies for the brevity, I&#x27;m on a tablet with an annoying keyboard.<p>There&#x27;s two things that make GPS trickier to jam:<p>- it&#x27;s spread spectrum with relatively hign coding gain. The signal itself is pretty much imperceptible above the noise floor until you phase lock onto the signal and despread. A really effective jammer would likely need to send out a similar but corrupted signal, not just noise.<p>- we know where the signal will be coming from. First that it will be coming from the sky, and once we have a copy of the almanac, we&#x27;ve got a pretty good idea where in the sky each SV will be. Directional antennas could further mitigate the jamming.<p>You&#x27;re not wrong about it being jammable, but it&#x27;s not trivially simple.<p>p.s. (because kb sucks) While the spreading codes for the civilian signal are commonly available and could be replicated in a jammer, the military spreading codes are not available. A well-funded adversary might be able to get ahold of them anyway, but it&#x27;d take some effort&#x2F;treason.