Simrad ES80 - Page 427

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Description
Eachseparateechogramviewoffered
bytheES80canshowyouadifferent
echogramtype.Whichtypetoseeis
chosenonthisEchogrampage.The
pagealsoallowsyoutoselectwhich
TVGcurvetouseforthechosen
echogram.
Thesetting(s)youchoosewillonly
bevalidforthecurrently"active"
echogram.Clickinanyechogram
viewtomakeit"active".The
"active"echogramviewisidentied
withathickerborder.SelectApplyto
Allifyouwishtousethechosensettingsonalltheechogramsofthesametype.
Tip
YoucanalsoselectTVGsettingwiththeTVGfunction.TheTVG(TimeV ariedGain)
functionislocatedontheActivemenu.
Details
TVG
Whenanacousticpulseissentthroughthewater,itwillgraduallyloseitsenergy.
Thegreaterthedistancebetweenthetransducerandthetarget(s),thegreaterthe
lossofenergy.
TheTVG(TimeV aribleGain)compensationisdesignedtocounteractthenatural
phenomenaofgeometricspreadandabsorptionloss.
TheTVGcompensationisexpressedasalogarithmiccurve.Youcanchoose
fromaselectionofcurves.Eachcurvehasadifferentslopecreatingadifferent
gaincompensation.EachcurveisidentiedwiththeequationXlogTVG.The
coefcient"X"isaninteger.Typicalvaluesfor"X"are10to40.
SelecttheTVGsettingyouwanttouse.SeveralTVGcompensationsettingsare
available.
•NoTVG
TVGcompensationisnotimplemented.Thissettingishardlyeverused.
•School(20logR)
Thisgainsettingoffersweakeramplicationclosetothebottom.Ithasbeen
designedtoprovidethebestechoesforschools.Thephysicalsizeofaschool
allowsyoutodetectitevenwithreducedgain.
Functionsanddialogboxes