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简介：Eightsetsofcoastalacoustictomography(CAT)systemsweredeployedduringNovember29toDecember10,2002atthecoastsonbothsidesofTokyoBaytomeasuretidalcurrentstructuresat15-mininterval.SoundtransmissionacrosstheTokyoBay(betweenYokohamaandChiba)wassuccessfullytraced,evenundersevereinterferencefromshipgeneratedwakesandbubbles.Tidalcurrentfieldschangingfromnorthwardtosouthwardflowarewellreconstructedbytheinverseanalysisoftravel-timedifferencedataforaperiodwiththebestsoundtransmissioncondition.ItissuggestedthattheCATisthemostpowerfultooltocontinuouslymaptidalcurrentfieldsinthecoastalseaswithheavyshippingtrafficandfisheriesactivity.

简介：在借精确集成方法的想法以后，一个精确集成转移矩阵方法(PITMM)被修改传统的转移矩阵方法建议。海底的壳能是加入了conicalcylindrical球形的壳被建模。由考虑ring-stiffeners的效果，革命的壳的地转移矩阵被PITMM精确地获得。在装配地转移矩阵进一个全部矩阵以后，动态模型被建立解决加入的壳的动态回答。由由修改波浪重叠方法(MWSM)在液体描述健全压力并且沿着加入的壳的顶点线并置点，最后，有限的使硬的海底的壳的结构、声学的回答能被联合PITMM和MWSM预言。现在的方法的有效性被把球形的壳的结构、声学的回答与存在结果作比较验证了。而且，海底的壳的结构、声学的回答上的模型截断，僵硬和厚度的效果被学习。

简介：Theunderwateracousticimagetransmissionsystembasedonthehigh-speedDSPdeviceTMS320C549hasbeenstudied.WeuseGoertzelalgorithmforsourcedecodingandMFSKformodulation.Turbocodeisusedforchannelcodinganddecoding.Thepurposeistoimplementunderwatervideoimagedatatransmission.

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简介：AnAcousticDopplerCurrentProfiler(ADCP)observationsitewassetupintheWesternSouthYellowSeafrom2012to2013tostudythelocalsuspendedparticlematters(SPM)distributionpattern.TheSPMconcentrationcouldbesemi-quantitativelyrepresentedbybackscatterintensity(Sv),convertedbytheechointensity(EI)ofADCP.ResultsshowtwotypesofSPMinthewatercolumn:thequasi-biologicalSPMandquasi-mineralSPM.Thequasi-biologicalSPMmainlyexistsinsummerhalfyearandisconcentratedabovethethermocline.Ithasperiodicallydiurnalvariationswithhighconcentrationatnightandlowconcentrationinthedaytime.Thequasi-mineralSPMislocatedinlowerpartofthewatercolumn,withsimilarrelationtomonthlytidalcurrentvariationallyearround.However,thedailyquasi-mineralSPMdistributionpatternsvarybetweensummerandwinterhalfyear.Thesunlightisthoughttobetheoriginfactorleadingtothediurnallyverticalmotionofthebiologicalfeatures,whichmightcausethediurnalSvvariation.UnlikeinwinterhalfyearwhentidalcurrentisrelativelysingledrivingforceofthemonthlySPMpattern,thehighspeedcurrentnearthethermoclineisalsoresponsiblefortheconcentrationofquasi-mineralSPMinsummerhalfyear.Thesedimentinputdifferencebetweensummerandwinterhalfyearcontributetothevarieddailyvariationofquasi-mineralSPMwithre-suspendedSPMinwinterandsedimentsfromYellowSeaMudArea(YSMA)insummer.Theseasonalvariationsinhydrodynamics,waterstructureandheavy-windincidentsaretheprimaryfactorsinfluencingthedifferentialseasonalSPMdistributionpatterns.