Measurements of the angular dependence of acoustic seafloor scattering in sandy sites

Jenna Hare; Anthony P Lyons; Gabriel R Venegas

doi:10.1121/10.0039373

Measurements of the angular dependence of acoustic seafloor scattering in sandy sites

J Acoust Soc Am. 2025 Sep 1;158(3):2225-2237. doi: 10.1121/10.0039373.

Authors

Jenna Hare^{1

2}, Anthony P Lyons^{1

2}, Gabriel R Venegas^{1

2

3

4}

Affiliations

¹ Center for Acoustics Research and Education, University of New Hampshire, Durham, New Hampshire 03824, USA.
² Center for Coastal & Ocean Mapping, University of New Hampshire, Durham, New Hampshire 03824, USA.
³ Department of Civil and Environmental Engineering, University of New Hampshire, Durham, New Hampshire 03824, USA.
⁴ Center for Ocean Engineering, University of New Hampshire, Durham, New Hampshire 03824, USA.

PMID: 40981491
DOI: 10.1121/10.0039373

Abstract

Seafloor scattering measurements are analyzed from a series of experiments (lasting from 3 weeks to 5 months) located in two shallow-water locations near Portsmouth, New Hampshire, USA. The experimental setup consisted of a tripod with transducers (operating at 38, 70, and 200 kHz) mounted ∼2 m above the seafloor and oriented at 17.5° grazing angle. Environmental measurements were obtained using a wave-sensing conductivity, temperature, and depth probe. Seafloor roughness was estimated using stereo imaging techniques on underwater photographs. The measured seafloor scattering strengths were averaged over calm periods between storm events. The overall levels and trends are compared to predictions from the small-slope approximation model. Data-model differences may be due to uncertainty in the model inputs and/or scattering mechanisms not captured in the model. In addition, the results are compared to reported estimates of scattering strength in sand-sized sediments. At a given frequency, grazing angle, and grain size, scattering strengths among all measurements vary up to ∼ 20 dB.