Peer-Reviewed Journal Details
Mandatory Fields
Jiashun Yu, Stuart A.Henrys, Colin Brown, Ivor Marsh, GarretDuffy
2015
April
Continental Shelf Research
A combined boundary integral and Lambert's Law method for modelling multibeam backscatter data from the sea floor
Published
()
Optional Fields
Multibeam backscatter acquisition Acoustic backscatter theory Lambert's Law Seafloor physical properties
103
60
69
A theoryhasbeendevelopedtomodelmultibeamacousticswathbackscatterangularresponseforatwo-dimensional seafloor usingacombinationofaboundaryintegralandaLambert'sLawapproximation.Inthis theoreticalapproachtheseafloor topographyisassumedtoaffectscatteringattwodifferentscales:arandom distributionofsurfaceroughness(mmtocm)oversmallspatialdistancescausesscattering,while theundulatingseafloor morphologyatlargerdistances(upto10sofm)affectstheanglesofincidence oftheacousticenergywiththeseabed.Thelatterdistancescalesarecomparabletothere-solution ofbathymetryacquiredbycommercialmultibeamsonarsinshelfseas,sothisvariationcanbedirectlymeasured,leavingthesmall-roughnessscale,notpracticallymeasureable,tobemodelledbyrandom variation.Themethodappliestoatwo-dimensionalseafloor modelwherethebathymetryisinvariantinadirectionperpendiculartothemultibeamswathbutitsphysicalproperties(acousticim-pedance, roughnessamplitudeandcorrelationlength)canvarylaterallyacross-track.Wedemonstratethe boundaryintegraltechniqueforarangeofseafloors withdifferingroughness.Wevalidateourresultsusing atime-domain finite-differencesolutiontotheacousticwaveequation,thecompositeroughnessmodel ofseafloor backscattering,andcomparisonofobservedmultibeamdataacrosscontrasting finegrainedsandtocourseshellhashseafloor transitioninGalwayBay,Ireland.
http://dx.doi.org/10.1016/j.csr.2015.04.020
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