Specifications

SimradSH90
AdjustingtheReverberationControlledGain(RCG)
Purpose
TheReverberationControlledGain(RCG)regulatesthereceivergainindividuallyfor
eachofthereceivingbeams.
TheRCGlterwillenhancethevisibilityofschools,andreducethereverberationfrom
bottomandsurfaceechoes.
Scatteredshcanbeperceivedasreverberation.TheRCGfunctionmustthereforebe
usedwithcareifscatteredschoolsaretobedetected.
Note
Whenthisparameterischangedonahorizontalmenu,thechosensettingisonlyput
touseonthehorizontalsonarpresentation.Ifyouchangetheparameteronavertical
menu,itisonlyappliedtotheverticalsonarslicepresentation.
Tip
WerecommendthattheRCGisactiveallthetime,butbecarefulinthevertical
presentation.TheReverberationControlledGain(RCG)worksbestonsmallschools.
Setting“1”isintendedforschools.Setting“2”ismadeforschoolswithhigherdensity.
Try“3”forschoolsclosetobottom,asthissettingwillalsoreducethebottomechoes.
Ifyouarelookingforscatteredsh,useRCGsetting“4”or“5”.
Settings“6”and“7”arealsointendedforschools,while”8”and“9”canbeusedon
scatteredsh.Thesesettingsusealternativealgorithms.
Relatedtopics
•WhatisRCG?onpage105
Procedure
1ClickeithertheHorizontalorVerticaltabtoopentherespectivemenu.
2ObservetheRCGbutton.
3Clickeithersideofthebuttontoleafthroughtheoptions,orthemiddleofthebutton
toopentheparameterdialog.
AdjustingtheTimeVariableGain(TVG)
Purpose
ThisparameterallowsyoutochoosetheTimeV ariableGainsettingintheSH90.This
functionwillautomaticallyadjustthegainintheSH90tocompensateforgeometric
spreadingandabsorption.
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