Three-dimensional imaging at 10.6 um to detect surface-laid mines

When choosing a route to transport troops and equipment in tactical scenarios, one requires a decision-making scheme that can make fast surveys of the possible paths. One of the main threats in this operation is the presence of scattered surface-laid mines. A possible solution would use an airborne long wave infrared (LWIR) active imaging system. In this paper, we report on one such system based on an intensity modulated waveguide CO2 laser. This system, which provides images in reflected intensity and relative range, has been tested on replica mines in laboratory. A relative range resolution of 2 mm is reported. Evidence of the insensitivity to the contrast in reflection and the absence of speckle noise for the relative range images is shown. A phenomenon associated with the erroneous evaluation of the relative range of inclined surfaces is identified.