title: Isolating scattering resonances of an air-filled spherical shell using iterative, single-channel time reversal.
abstract: Iterative, single-channel time reversal is employed to isolate backscattering resonances of an air-filled spherical shell in a frequency range of 0.5-20 kHz. Numerical simulations of free-field target scattering suggest improved isolation of the dominant target response frequency in the presence of varying levels of stochastic noise, compared to processing returns from a single transmission and also coherent averaging. To test the efficacy of the technique in a realistic littoral environment, monostatic scattering experiments are conducted in the Gulf of Mexico near Panama City, Florida. The time reversal technique is applied to returns from a hollow spherical shell target sitting proud on a sandy bottom in 14 m deep water. Distinct resonances in the scattering response of the target are isolated, depending upon the bandwidth of the sonar system utilized.
authors.affiliation: Physical Acoustics Branch, Code 7130, Naval Research Laboratory, Washington, DC 20375-5320, USA. zachary.waters@nrl.navy.mil
authors.forename: Zachary J
authors.initials: ZJ
authors.lastname: Waters
authors.forename: Benjamin R
authors.initials: BR
authors.lastname: Dzikowicz
authors.forename: Harry J
authors.initials: HJ
authors.lastname: Simpson