Just a quick perusal, leading to a lot of conjecture, I believe the Duga 3 was an attempt to mind control. Kind of like binaural beats and suggestive hypnosis.
Imagine a mentally healthy individual sticking their arm in the wind of an open car window, or pill rolling, or repetitively tapping. Initially the sensation may be shocking, but you get used to it, and when it is absent, in a sense you may expect it to remain. So the woodpecker being activated initiates a similar response.
They said this was only turned on at certain times. Maybe as a distraction, or as an attraction. Let's say the Russians turned it on when something positive was being played in the media or their subversive specific event was misspread in the media. Boom, activate the Duga 3.
Now take that technology, and fast forward to today. Implement it in your AC current through the LED backlights of your monitors or any other possibility it imposes. You can implement aversion or attraction by cycling the AC hertz.
It's probably woodpecker signals that spread over the horizon though like previously stated. Just really interesting that I had never heard of it.