Simrad SU90 - Controlling Gain and Range Settings; Adjusting Gain (Echo Sensitivity)

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381291/C
Tip
Ifyouworkinshallowand/orconnedwatersyoumaynditusefultoreducetheoutput
powertoavoidreverberation.
Someofourusersclaimthatreducingtheoutputmaybeusefulifyouarelookingfor
scatteredsh.
IfyouoperateintheclosevicinityofothervesselsthatarealsousingtheSU90,
interferencemaycauseproblems.Reducingtheoutputpowerisnotapracticalwayto
dealwithinterference.Itismoreefcienttochangetheoperatingfrequency.
Toinvestigateunknownand/orunfamiliartargets,someuserpreferto"reset"theSU90
byturningoffallthereceiverltersandadjusttheoutputpower .
Seaconditionsvary,sometimesdrastically.Theacousticconditionsarealsochanging.
Temperatureandsalinitylayersdifferfromonedaytothenext,andfromonepositionto
another.Itisnotpossibletoidentifysettingsthatwillprovidethebestdataatalltimes.
Procedure
1OpentheOperationmenu.
2SelectTxPower.
3Selecttherequestedoutputpower.
Selecteithersideofthebuttontochooseavalue.
Selectthemiddleofthebuttontoopenasmallmenuwiththeavailableoptions.
Relatedtopics
Choosingoperatingmodeandkeytransmitparameters,page48
Selectingthebestoperatingfrequency
TheFrequencyfunctionisusedtocontrolthecentrefrequencyoftheacoustic
transmissions(pings).Thecentrefrequencycanbechangedfrom20to30kHzinsteps
of1kHz.Alltypesofnoisematterwhenyouwishtondthebestoperatingfrequency.
Context
Alowerfrequencygivesyouabetterdetectionrangebecausetheattenuationlossis
smaller.Ahigherfrequencygivesyoubetterrangeresolution.Ahigherfrequencyalso
givesyounarrowerbeamsanda"sharper"image".
Noisefrominternalandexternalsourceshaveanimpactonthechoiceofoperating
frequency.Onespecicfrequencymayperformbetterthantheothersonyourvessel.
Tomeasurethenoiselevel,observethevaluepresentedontheNoisepageintheBITE
dialogbox.
SimradSU90OperatorManual