User manual

Functionsanddialogs
3PulseDuration
Thiscolumnspeciesthecurrentdurationofthetransmittedpulse.Youcan
manuallyselectadifferentduration.
IfyouclickAuto,theES70willautomaticallyselectthebestpulsedurationforthe
currentoperationalmode,depthandbottomconditions.
Tip
Thelengthofyourtransmittedpulseisveryimportanttohowyoucandetectsh.
•Ashortpulsedurationgivesyouaveryneverticalresolution.Thisallowsyou
todetectscatteredsh,andyoucanndthosethatmovenearthebottom.
•Alongpulsedurationthrowsalotmoreenergyintothewater,andthedigital
ltersusedbythereceiverarenarrower.
TheselterswillreducetheES70'ssensitivityfornoise,butthelengthofthe
transmittedpulsewillgiveyoustrongerechoes.Withthelters,alongerpulse
durationwillprovidelongerrange,butreducedverticalresolution.
Thistableshowstheavailablepulsedurationsforgivenfrequencies.TheX-axis
showspulsedurationsinµSwhiletheY -axisshowsfrequencyinkHz.An“x”
meansthatthepulsedurationisavailableforthegivenfrequency.
64128256512102420484096819216384
12kHz
xxxxx
18kHz
xxxxx
27kHz
xxxxx
38kHz
xxxxx
50kHz
xxxxx
70kHz
xxxxx
120
kHz
xxxxx
333
kHz
xxxxx
710
kHz
xxxxx
4Power
Thisparameterdisplaysandcontrolsthetransmitter’soutputpower.Outputpower
islimitedeithertothemaximumratingofthetransducer,orthemaximumratingof
thetransmitter,whicheveristhesmallest
.
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