Simrad SU90 - Adjusting the Intensity of the Echo Presentations; Changing the Tilt

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381291/C
Adjustingtheintensityoftheechopresentations
TheeffectoftheGainadjustmentisminimizedifyouapplyRCG(Reverberation
ControlledGain)andAGC(AutomaticGainControl).TheDisplayGainisapplied
towardstheendoftheltersequenceintheSU90.Thismeansthatyoucanuse
DisplayGainifyouarenotcompletelysatisedwiththeresultsoftheautomaticgain
functionality.
Context
DisplayGaincontrolsthe"amount"ofechothatisdisplayed,inotherwordsthe
"strength"or"intensity"oftheechopresentation.Thefunctionthusincreasesor
decreasesthepresentationoftheechocolours.UsethisparametertogetherwithGainto
adjusttheSU90sensitivity.
Forallpracticalpurposes,adjustingDisplayGainhasthesameeffectasadjustingGain.
AdjusttheDisplayGainsothatyoucanseethetargetswithouttoomuchnoiseand
reverberation.Thechosensettingisamatterofpersonalpreferences.
Procedure
1OpentheDisplaymenu.
2SelectDisplayGain.
3Adjustthesettingtotyourrequirements.
Tochangethesetting,movethecursorto
eithersideofthebutton.Selecttheleftside
ofthebuttontodecreasethevalue.Selecttherightsideofthebuttontoincreasethe
value.Selectthemiddleofthebuttontoopenit.Ifyouhaveakeyboardconnected
totheSU90,youcantypetherequestedvalue.
Relatedtopics
Controllingthegainandrangesettings,page56
Improvingtherecognitionofshandschoolsusingreceiverlters,page72
Changingthetilt
Inordertodetectshorschoolsinthewatercolumnyoumayneedtochangetheangle
ofthesonarbeams.Thesonarbeamscanbetiltedelectronicallyfrom-10to+60°in
1°steps.
Context
ThecurrenttiltisshownwithasolidlineintheV erticalview.IntheHorizontalview,the
currentsettingsforrange,gainandtiltareshowninthetopleftcorneroftheview.
At0°tiltthesonarbeamistransmittedparallelwiththeseasurface,while-60°tilt
willdirectittowardsthebottom.
SimradSU90OperatorManual