17 May 2006 Nonlinear acoustic landmine detection: comparison of off-target soil background and on-target soil-mine nonlinear effects
Author Affiliations +
Abstract
When airborne sound at two primary tones, f1, f2 (closely spaced near a resonance) excites the soil surface over a buried landmine, soil wave motion interacts with the landmine generating a scattered surface profile which can be measured over the "target." Profiles at the primaries f1, f2, and nonlinearly generated combination frequencies f1-(f2-f1) and f2+(f2-f1) , 2f1-(f2-f1), f1+f2 and 2f2+(f2-f1) (among others) have been measured for a VS 2.2 plastic, inert, anti-tank landmine, buried at 3.6 cm in sifted loess soil and in a gravel road bed. [M.S. Korman and J.M. Sabatier, J. Acoust. Soc. Am. 116, 3354-3369 (2004)]. It is observed that the "on target" to "off target" contrast ratio for the sum frequency component can be ~20 dB higher than for either primary. The vibration interaction between the top-plate interface of a buried plastic landmine and the soil above it appears to exhibit many characteristics of the mesoscopic/nanoscale nonlinear effects that are observed in geomaterials like sandstone. Near resonance, the bending (softening) of a family of increasing amplitude tuning curves, involving the vibration over the landmine, exhibits a linear relationship between the peak particle velocity and corresponding frequency. Tuning curve experiments are performed both on and off the mine in an effort to understand the nonlinearities in each case.
© (2006) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Murray S. Korman, James M. Sabatier, Kathleen E. Pauls, Sean A. Genis, "Nonlinear acoustic landmine detection: comparison of off-target soil background and on-target soil-mine nonlinear effects", Proc. SPIE 6217, Detection and Remediation Technologies for Mines and Minelike Targets XI, 62170Y (17 May 2006); doi: 10.1117/12.668752; https://doi.org/10.1117/12.668752
PROCEEDINGS
8 PAGES


SHARE
Back to Top