g. There are many types of barbed wire. The more common types are trip,
concertina, and knife-rest (Figure 2-24).
Barbed wire shows up on aerial
imagery as a regular, uniform line varying in shade from fight grey to black
depending first on whether or not the wire has been newly strung, and
second, on the texture of the terrain. Because of its size, you cannot see
the wire itself.
However, indications, such as posts, tracks, spoil, and
uncut or uncropped vegetation, provide a firm basis for positive
identification of barbed wire.
New wire sometimes appears light in shade
because of tracks and spoil disturbed while placing the wire.
reveal gaps in wire. Grass and weeds grow quickly through the wire and form
The pattern of the wire may indicate machine-gun positions
Figure 2-24. Wire Types.
Machine-Gun Positions and Wire Patterns.