- Conference date: 1-5 March 2004
- Location: La Jolla, California (USA)
Seafloor ripple reverberation is associated with a peak in the scattering frequency spectrum at a frequency around c/(2λ r cos θ), where c is the sound speed in water, λ r is the ripple wavelength, and θ is the incident grazing angle. In the vicinity of this peak, perturbation theory predicts the reverberation level to be high enough to be a concern for detection of targets buried under ripple. In order to validate such predictions, an experiment was conducted in the Naval Surface Warfare Center Panama City (NSWC‐PC) Facility 383, which is a 13.7‐m deep, 110‐m long, 80‐m wide test pool that has 1.5 m of sand covering the bottom. Backscatter reverberation levels from two bottom configurations were measured using a parametric source that was operated in the 1 to 10 kHz frequency range. One bottom configuration corresponded to a non‐rippled, near‐flat bottom. The second was a rippled bottom with a Gaussian spectrum centered on a wavelength of 20 cm. The rippled bottom was artificially formed with the aid of a sand scraper. Results showed the reverberation levels were significantly higher in the 3 to 5 kHz frequency range for the rippled bottom than for the non‐rippled bottom. The maximum reverberation level for the rippled bottom occurred at 4 kHz, which is consistent with perturbation theory predictions.
- Perturbation theory
- Acoustic scattering
- Acoustical measurements
- Scattering measurements
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