Installation manual
SimradES70
Pelagicechogram
Thepelagicechogramappearsverysimilartothesurfaceechogram.However,the
biomasscalculationsarenotlimitedbythebottomdetection.
Example11StartRangeinapelagicechogram
Inapelagicechogram,settheStartRangevalueto20meters.Thiswillmakethe
echogramstartfrom20metersbelowtheseasurface(providedthatthetransducer
offsethasbeendened).SetRangeto40meters.Theechogramwillnowshow
theareafrom20metersbelowtheseasurface,anddownto60metersbelowthe
transducer.Providedthatthedepthislargerthan60meters,thebottomcontour
isnotshown.
Thebiomasscalculationsarenotrestrictedbythebottomdetection.Thismeansthatthe
bottomechowillbeincludedincalculationsifitappearswithinthechosenrange.
Trawlechogram
Theechogramcoverstheverticalopeningofthetrawlwithreferencetothedepthof
theheadrope.
Inadditiontothetrawlopening,theechogramcoversacertainrangeoverandunderthe
trawlopening.ThisrangeissetbyadjustingtheRangeandStartRangeparameters.
Trawlsensorsystems(typicallySimradITIandPI)communicateheadropedepth,as
wellasthedistancefromtheheadropetothefootrope(trawlopening),totheES70at
regularintervals.Thisinformationisrequiredforthetrawlechogramtobegenerated.
Withoutthedepthoftheheadrope,theechogramwillappearlikeastandardpelagic
echogramcontrolledbytheRangeandStartRangeparameters.
Thedistancefromtheheadropetothefootrope(trawlopening)canbemanuallyset
intheTrawldialog.Thisisusefulfortrawlsensorsystemsnotmeasuringthetrawl
opening,orwhenthemeasureddistanceisunreliable.TheTrawldialogalsoallowsyou
toenterthedistancefromthevesseltothetrawlopening.Thedepthoftheheadrope
musthoweverbeprovidedbythecatchmonitoringsystem.
IntheTrawldialogyoucanalsodenethedistancefromthevesseltothetrawlopening.
Example12StartRangeandRangeinatrawlechogram
Inatrawlechogram,settheStartRangevalueto–5meters.Thiswillmakethe
echogramstartfrom5metersabovetheheadrope.Ifthetrawlopeningis20
meters,setRangeto30meters.Theechogramwillnowshowtheareafrom5
metersabovetheheadrope,downacrossthetrawlopening,anddownto5meters
belowthefootrope.Onapelagictrawl,thebottomcontourisnormallynotshown
withthesesettings.Onabottomtrawl,thebottomcontourisshownoncethetrawl
openingislessthan5metersoverthebottom.
ThebiomasscalculationsinaTrawlechogramarenotrestrictedbythebottomdetection.
Thismeansthatthebottomechowillbeincludedinthecalculationsifitappearswithin
thechosenrange.
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