Simrad ST90 - Page 57

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•PulseType
ThePulseTypefunctionallowsyoutoselectthe"shape"ofthetransmittedpulses
("pings").Differentshapeshavedifferentqualities.Whichpulsetypetousedepends
onthecurrentenvironmentalconditions,yourrangetothetarget(s)andthetypeand
speedofthetarget(s)youareobserving.
•Bandwidth
TheBandwidthfunctionallowsyoutoselectthefrequencyrangeintheHyperbolic
FrequencyModulated(HFM)transmissions.
•Frequency
TheFrequencyfunctionallowsyousetthecentrefrequencyfortheHyperbolicFrequency
Modulated(HFM)andLinearFrequencyModulated(LFM)transmissions(pings),and
theoperatingfrequencyfortheContinuousWave(CW)pings.
•HorizontalTXSector
TheST90transmitsinaswathwithmaximumhorizontalopeningangle360°
omnidirectional.BymeansoftheHorizontalTxSectorfunction,youcanchangethis
openingangleto180,120,90,60or30°.ThefunctionisonlyavailableintheHorizontal,
PlaneandInspectionviews.
•VerticalTXSector
TheST90transmitsinaswathwithmaximumverticalopeningangle94°.Bymeansof
theVerticalTxSectorfunction,youcanchangethisopeningangletoN/A.Thefunctionis
onlyavailableintheVerticalandNavigationviews.
•RangeProjection
Thedistancetoatargetlocatedanywhereinthewatercolumncanbemeasuredintwo
ways.Thiscaneitherbethehorizontaldistancetothetarget(True),oralongthetiltangle
(Slant).TheRangeProjectionfunctiondeneshowthisdistanceismeasured.
•AGC(AutomaticGainControl)
TheAGC(AutomaticGainControl)functionrunsanautomaticanalysisoftheecho
strength.
•RCG(ReverberationControlledGain)
TheRCG(ReverberationControlledGain)functionremovesunwantedreverberation
fromthebottomandorfromtheseasurface.Thisenhancesthevisibilityofschools.It
mayhoweveralsoremovescatteredshfromthepresentation.
•BottomFilterThreshold
TheST90providesabottomltertoreducethesometimespowerfulechofromthe
seabed.Thislterisusefulifyoutrytondshclosetothebottom.SelectaBottom
FilterThresholdvaluetocontrolthe"strength"ofthelter.Ahighernumericalincreases
thelterefciencyandreducesthebottomechoaccordingly.
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