re: “GPS is totally vulnerable to spectrum jamming radio signals.”
Who’s jamming you? If it’s “jamming”, the jammer can be found toot-sweet.
If *anything* emits, trust me, I can located it (AND so can others). I do this on a regular basis, usually for power line noise, and THOSE sources can be pretty intermittent at times, located on a pole almost anywhere in terms of accessibility. That’s when a mountain bike and hiking boots come in to play.
The jamming is from other satellites thousands of miles away. indefensible. We have them too.