I'm wondering how robotic lawnmowers (or invisible dog fences) are able to sense the perimeter wire? Thinking inductive sensing or maybe radio frequency?
If anyone knows more on how these systems work I would appreciate any info/links.
Pet fence - Wikipedia, the free encyclopedia
It's more close inductively coupled than it is via RF, somewhat like AM radio, where what you pick up is actually the magnetic portion from a loop stick antenna not the electric portion that an FM or higher frequency antenna might use.