I forgot. The first thing I built for the diorama was an Empire droid. The idea was that like the droids ejected to Hoth from the Star Destroyer, these smaller Intruder detection units would be sent into the atmosphere, where the larger outer unit, would then break open and jettison many many droids, each would then rocket off to different areas.
On approaching the ground, the outer cannister would break open and the internal droid would embedd itself in the ground to a pre-defined level. The antennas would deply and the droids would begin to communicate back to the Star Destroyer and to each other to form a large wide ranging net.
In the event of Intruder detection, the droids could plot the route by communicating amongst them selves and send info to the Star Destroyer or indeed to any local Scout Trooper units.
The Droid was made from 1/6 ammo cases, bits of tanks and metal rods for the aerials.
In the diorama, this will sit amongs the foilage, and would have just notified the tropper, sitting on his bike, of an approaching threat. The Trooper, a seasoned pro...springs into action.