Radar Identification of Hostile Fire by Means of the Electromagnetic Complex Natural Resonances of Projectiles

The authors discuss and demonstrate the feasibility of using ultra wide band microwave radar to detect and identify small arms fire. Detection and tracking is by standard radar techniques, but identification is carried out by exciting the projectiles Complex Natural Resonances and using this aspect independent information to assign a caliber to the incoming projectiles. The typical sizes of small arms projectiles (calibers 5.56 mm through to 13 mm) imply that ultra wide band illumination in the microwave region of the spectrum between 1.5–5.5 GHz is required to excite these object’s fundamental resonances. The authors give a discussion of the effects of motion on the quality of the complex natural resonance data obtainable and present both simulated and laboratory data for the radar cross section of three different caliber projectiles (5.56 mm, 7.62 mm and 13mm).