its can be used together with haarp to stimulate human bodies (wich become a reciever from the induced micro-metals)
or just to get a ping back (think of sonar, wich human bodies reflecting the signal)
logical thinking would dictate that tha ayls would have superior tec anyway, so i would argue that they could penetrate whatever we put up. Only way around it would be an agreement of some sort (with greýs, to keep the ppl on lower vibration, or the other way around with someone(thing) else to prevent something from entering).
Everything is possible
https://www.hooktube.com/watch?v=w4Phln_z7-E
i´ll give you an example of admited modification of the weather, now think what is done behind closed doors (military)
https://www.businessinsider.de/china-sets-aside-millions-to-control-the-rain-2016-7?r=US&IR=T
(You) got the point