USA

[CharlesHarris]

I am well acquainted with some people at Raytheon who produce battlefield sensors being used along the Afghanistan border with Pakistan. What can be said is that you don't need observers on the ground. Devices disguised as common rocks or cattle dung can be distributed by air, scattered over a wide area and will blend in with the surroundings. A few might be discovered, but even in a dedicated ground search you would not find them all. I cannot describe how they work or their capabilities, but suffice to say battlefield commanders can have in real time an accurate assessment of activity in the covered area, whether it is human foot traffic, animals on the hoof, mechanised vehicles, etc. It is then easy to direct a Raptor drone to investigate further and respond as needed.

The "Virtual Fence" beats a wall.