Specifications

SimradSH90
Notethatthislterisbuiltintothesoftware.Itisnotavailableasafunctionyoucan
controlonthemenusystem.
Frequencyselection
Themultiplefrequencyselectionscanbeusedforsuppressionofinterferencefrom
othersonars.
Thesoundabsorptioninsaltwaterincreaseswiththefrequency,thusgivingthelower
frequenciesalongerdetectionrange.
Relatedtopics
•Changingtheoperationalfrequencyonpage35
AGC(AutomaticGainControl)
TheAGC(AutomaticGainControl)sensestheecholevelinseveraldirections,anduse
thisasabasisforadjustingallthereceiverbeams.TheAGCwillthusprovideautomatic
scalingofthedatainordertomaintainproperdynamicrangebasedonallechovalues
Thestrengthoftheltercanbeselectedinthemenu.
Relatedtopics
•AdjustingtheAutomaticGainControl(AGC)onpage36
•WhatisAGC?onpage102
RCG(ReverberationControlledGain)
TheRCGfunctionadjustthepicturetominimizeinuencefrombottomandsurface
reverberation.
Thestrengthoftheltercanbeselectedinthemenu.Withmaximumstrengthisselected,
theRCGwilleffectivelyreducethebottominshallowwater,whilevariationsonthe
bottomwillbedisplayed.Notethatscatteredshcanbeperceivedasreverberation.The
RCGltermustthereforebeusedwithcareifscatteredschoolsaretobedetected.
Relatedtopics
•AdjustingtheReverberationControlledGain(RCG)onpage38
•WhatisRCG?onpage105
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