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Comment by typewithrhythm | Hacker News Reader

You can't really beat a jammer, sure you can compete for power output, but there is no real stopping it.

Aircraft and military positioning concepts are evolving towards more map and dead reckoning, lessening the benefit of GPS jamming.

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The reason that dead reckoning was inaccurate was because of clock and vector inaccuracies. Looking at the advances in clockpieces and gyroscopes (both of these has benefitted over the optical revolution) over the years, I am not shocked that dead reckoning is back in vogue.

Dead reckoning is also inaccurate due to unknown winds. Even if you take off with the best available forecast, it’s often wrong by 5mph+. After three hours your position is off by 15 miles. That’s not remotely good enough for most aviation purposes.

Dead reckoning based on heading and time alone, but if you have a good INS it's not affected by wind only by accuracy of the gyroscopes/sensors.

Current systems drift by about 0.5 miles per hour. And that's normal commercial grade systems, I'm sure the military has an option for better systems if they need them.

As t0mas88 said, you don't rely on the measured speed of the aircraft/ship, you rely on gyroscopes (which are much more resistant to external factors), and both clocks and gyroscopes have improved signifcantly (clocks are now better than cesium atoms - read about atomic clocks) and so are gyroscopes (again, optical gyroscopes that are miles better than mechanical ones).

Portable clocks are not better than static caesium clocks, and optical clocks which are better than caesium clocks are not portable.

Eh, not smartphone-like portable, sure, but publicly (https://english.kyodonews.net/news/2025/03/c0945eb14bb6-japa...) it can now be fitted on a ship or submarine (and I won't be surprised if there is classified miniturization out there).

Correct me if I’m wrong, but wouldn’t a jammer be very easy to disable kinetically?

A missile would simply have to follow the jammer’s signal.

The obvious problem with this approach: destroying a jammer in foreign country with a missile is an act of war.

Janming is an act of war too.

Sure, use energy beams to strike their jammers.

Be an interesting feature to add to the AGM-88E.

Missels are expensive. Jammers can be farther away than a cheap drone can reach.

Jammers often move. Your missle often cannot manovure well enough to hit. jammers often turn off - if you missle is detected they turn the jammer off and move it. They are often running more than one jammer so getting one to turn off isn't going to matter.

Plus aircrafs can use Earth gravity map. Sensors became accurate enough to detect minuscule changes in gravity strength to position aircraft to few hundred meters.

You can defeat a jammer if you are willing to use more spectrum than your opponent and/or can sacrifice information rate.

True, but both very hard to do in a system that's deployed to space and (heavily regulated) avionics part of aircraft that get upgraded very infrequently, to say nothing of the billions of other civilian receivers.

What if you used directional antennas?

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