It would be easier to, you know, secure wireless communications to begin with. It's not like the Feds couldn't arrange to have stingrays that are properly keyed. (And there's always CALEA.) Yes, I know, it would only be easier for new kit, but it will take a long time to get it deployed. But every year we delay this makes the pain worse.

"The best time to plant a tree was 20 years ago. The second best time is now."

Phased arrays of antennas can compute the incoming direction of a signal entirely through signal processing and do not require a motorized platform.

purely Rx phased arrays, unless very large, do not have nearly the gain (in dBi) of a good parabolic or horn. and not nearly as much directional discrimination as a good sized (90cm) parabolic.

in a phased array that is also a Tx this can be partially compensated for with higher dBm output power from the radio itself, but that's not the usage scenario we're talking about here.

Can LTE carrier networks not act as an enormous observation system for unauthorized IMEI catchers?