Perimeter wire with sensors for robotic mower

[grint]

Many of the robotic mowing options out there use a perimeter wire pegged down to define a boundary. Can the pegs be numbered and when a mower gets near the perimeter it senses (for example) Peg 3. How would
a} the individual pegs get their own identity
b} since they would be (shallowly) below soil how could a robotic mower identify them through the soil?
Thanks

[Yveaux]

@grint Nice topic!
But googling immediately led me to this site: http://www.ardumower.de/index.php/en/induktion
Seems quite easy to build yourself.

[grint]

@Yveaux - hi - I've seen that and spoken to them, but they don't use the system with numbered pegs that I'm suggesting to get a clearer map of the robot's location. They simply use a perimeter wire. Their lane-by-lane mowing doesn't work very well, because... knowing where the robot is within the defined perimeter is pretty hard. Cheers,

[Yveaux]

@grint how would a compass sensor perform in a lawnmower robot?