Simrad ES80 User Manual

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acousticenergyscatteredbyagroupoftargetsisthesumoftheenergyscatteredby
eachindividualtarget.Thisassumptionholdswellinmostcases.Thetotalacoustic
energybackscatteredbytheschooloraggregationisintegratedtogether,andthis
totalisdividedbythe(previouslydetermined)backscatteringcoefcientofasingle
animal,givinganestimateofthetotalnumber.
http://en.wikipedia.org/wiki/Fisheries_acoustics,March2015
TheES80recordsallthetargetsfromthesmallestplanktontothelargestwhale.The
biomassvalueisanindicatortohowmuchshyoucurrentlyhaveinthebeam.Every
singleshwillemitanecho,andthesumofalltheseregisteredechoesarepresentedas
anumber.Smallerorganismssuchasplanktonwillalsoemitechoes,buttheseareso
weakthattheywillhardlyinuenceonthetotalbiomass.
Thebiomassvalueprovidesyouwithinformationabouttheshabundance,andassuch
itmayhelpyoutodecideifitpaysofftostartshing.However,youmustconsiderifthe
biomassvalueisaresultoflargeamountsofplanktonorbait,orifyouhave"realsh"
belowthekeel.Thebiomassvalueisrelative,andaftersomeuseyourexperiencewillbe
avaluablefactorwhenthedecisionismade.
Note
Youmayexperienceveryhighandunrealisticbiomassvaluesthatdonotmatchthe
informationintheechogram.
IfyouhaveotherechosoundersorsonarsrunningasynchronouswiththeES80,these
systemsmaycauseinterference.TheES80maydetectandmeasurethetransmitpulses
fromotherhydroacousticsystems,andthesepulseshaveaneffectonthebiomass
calculations.
TrythePing-PingFilter.ThePing-PingFilteranalysesthehistoricalinformationfrom
previousconsecutivepingsinordertoremoveunwantednoiseandinterferencefromthe
ES80presentation.
Toavoidallinterference,afullsynchronizationofthevariousacousticinstrumentsis
required.Ifyourownvesselproducesexcessivenoisethiswillalsobetakenintothe
biomasscalculationsandgiveyouinaccuratedata.
Itispossibletoconvertthebiomassindextoweight(forexampleinmetrictons).Based
onpracticaluseoftheES80indifferentsheries,youwillsoonbeabletoestimatethe
weightwhenyouknowthetypeofshandtheirsizes.
Tip
TheBiomassLineallowsyoutomonitorthecurrentbiomassintheechogram.This
functionwritesanextrathickandbrightlycolouredcurveontheechogram.The
BiomassLineshowsyouthemeasuredbiomassforeachindividualping.Youcanchange
thescaleofthecurvetottheverticalspaceavailableontheechogram.Toenablethe
BiomassLinefunctionandchangethescale,usetheLinespageintheEchogramdialog
box.
SimradES80ReferenceManual

Simrad ES80 Specifications

General

Brand	Simrad
Model	ES80
Category	Marine Equipment
Language	English