Antenna tech has moved way beyond what was possible in the days GPS was invented. Planar arrays and MIMO are ubiquitous and cheap.
These antennas have a very good idea of where the signal is coming from, due to delay measurements and can detect and filter ambient noise. They are super hard to jam. The reason why drones have become such a PITA is that these inexpensive antennas are very hard to defeat even with military jammers.
If this becomes a geniune need in the civilian sector, then I'm sure the tech is up to the challenge.
The tech is already there, but the reason those antenna are not widely used is that they used to fall under ITAR, so no US companies want to touch those for civilian uses. Of course Turkey and China is not US so they don't give a damn about ITAR compliance, and so you can buy those anti jam antennas out of alibaba.
Brad Parkinson, the father of GPS and PNTAB, they've been trying to lobby the US government to remove ITAR from that technology so the civilian can benefit from anti jamming, and finally they managed to do it sometime last year. Now it falls under EAR
There's also a bunch of Western stuff you can buy off the shelves. MIMO tech is standard in every Wifi 5+ router, Cars have pretty sophisticated electronically steered radars nowadays, boats even more so. 5G towers also have phased array antennas. This tech is everywhere in consumer or industrial stuff.
Not sure what makes an antenna/sensor ITAR restricted, I suspect if you try optimizing it to military use-cases, you'll get hit with ITAR, but I suspect Brad Parkinson is right - security through obscurity just doesn't cut it any more.
I remember in the 90s, computer security was either missing or an afterthought (you could bypass the Win98 password prompt by pressing escape in the release version). Thankfully the industry got together and figured it out.
Now everyone else needs to follow suit. We already have a bunch of examples of assuming security does not matter (hackable cars, meters that can be switched with a Flipper zero).
> Not sure what makes an antenna/sensor ITAR restricted,
Intentionally-designed anti-jam features (active-nulling and electronically-steerable receivers made for this purpose) marketed towards GNSS applications are EAR items (and are incorporated into ITAR by reference.)
> These antennas have a very good idea of where the signal is coming from, due to delay measurements
"These antennas" is doing an impossibly large amount of work. What you are describing here is a delay-calibrated coherent receiver, not an antenna, and it's absolutely not "inexpensive" to pull this off.
With passive antennas, most of the attenuation of adversarial signals is being done by the relatively-high-directionality of planar arrays: off-boresight signals have far greater attenuation with these (20dB? - tricky because you still do want good satellite data close to the horizon), and most garden variety jammers are terrestrial and off-axis.
Still, these signals are always below the noise floor and mostly unsigned, it's somewhat easy for an airborne (or spacefaring) jammer to fully drown out, replay/time-shift, or spoof the signal.
These antennas have a very good idea of where the signal is coming from, due to delay measurements and can detect and filter ambient noise. They are super hard to jam. The reason why drones have become such a PITA is that these inexpensive antennas are very hard to defeat even with military jammers.
If this becomes a geniune need in the civilian sector, then I'm sure the tech is up to the challenge.