Bistatic scattering in sediments: Comparison of model and scaled tank experiments at 238 kHz

R. Howey, P. Blondel

Research output: Contribution to conferencePaper

Abstract

Multiple-aspect scattering is increasingly used to investigate seabeds and objects, buried or not. However, high-frequency scattering processes on/in sediments need to be better understood, particularly when the structure and/or composition of these sediments is not fully homogeneous. Scaled tank experiments were conducted with a 238-kHz sonar (10° beam-width) imaging a silt seabed at 45°. Scattering angles varied between ∼16° and ∼70° (50 distinct values); bistatic angles varied 40° either side of in-plane with a 2.5° step (33 distinct values). Bottom returns were picked through two methods (automatic and manual) and converted into scattering strengths. This large dataset was compared with the APL-UW model for bistatic scattering, intended for 10-100 kHz but successfully tested at 240 and 455 kHz by other workers. Recursive fitting of model parameters to the experimental values assesses the influence of sediment variations (backed by microscope measurements) and the importance of even small tilts in the surface of the sediments. More importantly, they show the importance of the beam pattern and the sidelobes in the accurate calculation of bistatic scattering strengths. These results can be used to further validate scattering models as well as to design future surveying strategies.

Conference

Conference7th European Conference on Noise Control 2008, EURONOISE 2008
CountryFrance
CityParis
Period28/06/083/07/08

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scattering
sediment
experiment
sonar
comparison
tilt
surveying
silt

Cite this

Howey, R., & Blondel, P. (2008). Bistatic scattering in sediments: Comparison of model and scaled tank experiments at 238 kHz. 3353-3358. Paper presented at 7th European Conference on Noise Control 2008, EURONOISE 2008, Paris, France.

Bistatic scattering in sediments : Comparison of model and scaled tank experiments at 238 kHz. / Howey, R.; Blondel, P.

2008. 3353-3358 Paper presented at 7th European Conference on Noise Control 2008, EURONOISE 2008, Paris, France.

Research output: Contribution to conferencePaper

Howey, R & Blondel, P 2008, 'Bistatic scattering in sediments: Comparison of model and scaled tank experiments at 238 kHz' Paper presented at 7th European Conference on Noise Control 2008, EURONOISE 2008, Paris, France, 28/06/08 - 3/07/08, pp. 3353-3358.
Howey R, Blondel P. Bistatic scattering in sediments: Comparison of model and scaled tank experiments at 238 kHz. 2008. Paper presented at 7th European Conference on Noise Control 2008, EURONOISE 2008, Paris, France.
Howey, R. ; Blondel, P. / Bistatic scattering in sediments : Comparison of model and scaled tank experiments at 238 kHz. Paper presented at 7th European Conference on Noise Control 2008, EURONOISE 2008, Paris, France.6 p.
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