Abstract: Embodiments relate to noncontact determination of nonlinearities. Initially, a first and second primary signal are preconditioned to produce a first and second tone capable of reaching a target granular media. Using a sound source, the first and second primary signals are emitted such that the first and second primary signals combine in a nonlinear fashion in the target granular media to produce low frequency acoustic tone that is a difference between the first and primary signals. An acoustic pulse is received by an acoustic receiver, and a quadratic nonlinearity coefficient and an acoustic pressure field are determined based on the acoustic pulse. At this stage, a sediment shear strength of the granular media is correlated to the quadratic nonlinearity coefficient to generate a shear strength lookup table.

Abstract: Embodiments relate to noncontact determination of nonlinearities. Initially, a first and second primary signal are preconditioned to produce a first and second tone capable of reaching a target granular media. Using a sound source, the first and second primary signals are emitted such that the first and second primary signals combine in a nonlinear fashion in the target granular media to produce low frequency acoustic tone that is a difference between the first and primary signals. An acoustic pulse is received by an acoustic receiver, and a quadratic nonlinearity coefficient and an acoustic pressure field are determined based on the acoustic pulse. At this stage, a sediment shear strength of the granular media is correlated to the quadratic nonlinearity coefficient to generate a shear strength lookup table.