Kongsberg EA440 - Acoustic Noise Reduction Strategies

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392616/B
Acousticnoise
Topics
Contributingfactors,page24
Selfnoise,page26
Ambientnoise,page28
Electricalselfnoise,page28
Somemeanstoreduceacousticnoise,page29
Contributingfactors
Severalfactorsarecontributingtotheperformanceofthehydroacousticequipment
usedonboardavessel.
Factorscontributingtotheperformanceofthehydroacousticequipmentusedonboarda
vesselare:
•Thequalityandpropertiesofthetransmittedsignal
•Thequalityofthereceivingsystem
•Theoperationalsettingsmadeduringoperation
•Thepropertiesofthetarget(s)
•Thesignal-to-noiseratio
Themajorityofthesefactorscanneitherbecontrollednorimprovedbymeans
ofinstallationmethodsortransducerlocations.Thequalityandpropertiesofthe
transmittingandreceivingsystemsarekeyfactorsduringourproductdevelopment,while
ourenduserdocumentationaimstohelptheusertomaketherightltersettingsduring
operation.Asforthetargetproperties,thereisnothinganyofuscandowiththose.
Thesignal-to-noiseratio,however,canbeimprovedbymakingthecorrectchoices
duringinstallation.
Signal-to-noiseratio(oftenabbreviatedSNRorS/N)isameasureusedin
scienceandengineeringthatcomparesthelevelofadesiredsignaltothelevelof
backgroundnoise.Itisdenedastheratioofsignalpowertothenoisepower,often
expressedindecibels.Aratiohigherthan1:1(greaterthan0dB)indicatesmore
signalthannoise.WhileSNRiscommonlyquotedforelectricalsignals,itcan
beappliedtoanyformofsignal[...].
http://en.wikipedia.org/wiki/Signal_to_noise_ratio(September2013)
Thesignalistheechothatwewanttoknowsomethingabout,whilethenoiseisany
unwantedsignalsordisturbances.Theechomustbedetectedinthenoiseandthereforeit
EA440Installationmanual