Analysis of bistatic mid-frequency seamount scattering

During the Office of Naval Research (ONR) New England Seamounts Acoustics (NESMA) experiment, low- to mid-frequency acoustic measurements were made of scattering from steep and irregular seamount flanks. These measurements included bistatic scattering from a stationary source (operated by Scripps Institution of Oceanography) to a towed horizontal line array (the Penn State Three Octave Research Array). The use of broadband waveforms and horizontal beamforming allows the separation of seabed/surface interaction and the azimuthal extent of scattering from the bathymetrically complex and acoustically rough seamount flank. The impact of these features is seen in the form of anisometric, out-of-plane scattering with an angular extent greater than 30 deg. Acoustic receptions appear to have significant incoherent energy due to seamount roughness, but also contain deterministic components from specific regions of the seamount flank. This talk will discuss acoustic measurements and analysis, the spatial distribution, and statistical characteristics of scattered returns.