Target Identification via Laser-Material Interaction

The Advanced Tactical Laser (ATL) is being developed for precision strike missions utilizing a directed-energy laser weapon mounted to or in an aircraft to engage ground or airborne targets. When there is some uncertainty about the visual identification of targets, the coherent radiation from the ATL assists determination of targeting by probing the material and surface characteristics of the irradiated object. Backscattered radiation from potential targets can be analyzed for changes in polarization, speckle size and modulation depth, and dependence of backscattered intensity with angle. These quantities all depend upon the composition and surface topology of the object being irradiated. Coupled with a traditional passive sensor system, the laser-material interaction can provide additional discrimination information to the aircrew when attempting to positively identify a target, or actively avoiding a particular type of target in a cluttered or obscured area. Nanohmics Inc. will use the fundamental physics of scattering to develop insight and expectations regarding the scatter characteristics of a variety of potential target materials. We will use our existing scatterometer instrument to verify the predictions of the analytical model and to demonstrate the performance of candidate target discrimination algorithms.