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Activemenu
TheActivemenuoffersparametersrelatedtocurrentviewsanddatapresentationsshownby
theST90.
Howtoopen
SelecttheActiveicon.
TheiconislocatedundertheMainmenu.Selecttheicon
onemoretimetoclosethemenu.
Description
Themajorityofthechoicesprovidedbythismenuare
self-explanatory.Onlyspecicfunctionsofparticular
interestareexplainedwithbriefdescriptions.Fordetailed
informationabouteachfunctionanddialogbox,referto
theST90Referencemanualorthecontextsensitiveon-line
help.
Thechoicesinthethismenudependsonwhichviewin
theST90presentationthatiscurrently"active".Themenu
maythereforechangefromoneviewtoanother.Thename
ofthecurrentlyactiveviewisidentiedatthetopofthe
menu.Thescreencapturemaynotshowyouallthemenu
choices.
Note
Beforeyoucanchangethesettingsrelatedtoaview,youmustclickinsidetheviewto
activateit.Thechangesyoumakearebydefaultonlyvalidfortheactiveview.Severalof
thefunctionsofferApplytoAll.IfyouselectApplytoAllyoursettingisappliedtoall
theviewsinthecurrentpresentationmode.
•TVG(TimeVariableGain)
Whenanacousticpulseissentthroughthewater,itwillgraduallyloseitsenergy.The
greaterthedistancebetweenthetransducerandthetarget(s),thegreaterthelossof
energy.TVG(TimeV ariableGain)compensatesforthelossofacousticenergydueto
geometricspreadandabsorption.
•Ping-PingFilter
ThePing-PingFilteranalysesthehistoricalinformationfrompreviousconsecutivepings
inordertoremoveunwantednoiseandfalseechoesfromtheST90presentation.
SimradST90QuickStartGuide