High frequency modulation approach for the nonlinear seismo-acoustic detection of buried landmines

Abstract

Buried in soil, landmines exhibit distinguishable nonlinear dynamic characteristics. These characteristics have been successfully used for nonlinear acoustic/seismic detection of both antipersonnel and antitank landmines. Despite a high potential of the nonlinear acoustic landmine detection technique, its utility is currently limited by a relatively high noise level of the LDV at frequencies typically used for landmine detection. To mitigate this limitation, we propose a modulation approach that exploits a nonlinear interaction of the low frequency resonance vibrations and higher frequency sound waves. The result of the modulation is manifested in a high frequency range as additional spectral components at the combination frequencies. The nonlinear response of the soil-mine dynamic system measured at the combination frequencies is used for the detection of the buried landmine. Exploring the higher frequency range has another benefit of using a directional high frequency sound source.