Resonance and Nonlinear Seismo-Acoustic Land Mine Detection

Since WWII acoustic echo-location method utilized in sonars has been one of the primary approaches for detecting underwater mines. However, earlier attempts to replicate sonar approach and its modifications for detection of landmines were not successful. For example, Caulfield, 1989, House & Pape, 1994, Don & Rogers, 1994 suggested the use of acoustic impulse reflection from soil. A buried object is detected by measuring a relative change in acoustic reflectivity of soil. However, compared to water, soil is an extremely inhomogeneous medium exhibiting wide variations in the physical properties: density, porosity, moisture content, etc. These variations often have a spatial scale comparable with the size of a mine creating respective variations in acoustic reflectivity regardless of presence of buried mines. Another significant drawback of these methods is their inability to discriminate mine from clatter with similar acoustic reflectivity (rocks, tree roots, etc.) The breakthrough in acoustic landmine detection had occurred with the discovery of landmine’s resonance and nonlinear behaviors.