Installation manual

SimradES70
3IncreasetheBottomBacksteplevel(makeitmorepositive).
Atypicalsettingwouldbeapproximately-30dB,butyouwillneedtoexperiment
tondthebestvaluefortheoperationalfrequencyandthecurrentbottomand
seaconditions.
TheES70willnowprovideincreasedpenetration,andshowyouadetectedbottom
thatisslightlydeeperthantheactualvalue.Thiswillcausetheatshtobeshown
asiftheywerelocated“above”thebottom.
4ClickOKtosavethecurrentsettingsandclosethedialog.
Howtoadjustthebottomdetectiontondseagrass
TheES70providestheBottomBackstepparameterintheBottomDetectordialog.Ifyou
haveanOlexsystem,youcanusethisparametertoenhancethedetectionofseagrass.
→Aboutbottomslopesonpage115
1ClicktheActiveiconundertheMainmenutoopentheActivemenu.
→Activemenuonpage107
2OntheActivemenu,clickBottomDetectortoopentheBottomDetectordialog.
Thisdialogisusedtodenevariousparametersassociatedwiththebottom
detection.Theseincludethedepthrange,wheretheES70searchesforthebottom.
3DecreasetheBottomBackstepleveltoalowervalue(makeitmorenegative).
Atypicalsettingwouldbeapproximately-60dB,butyouwillneedtoexperiment
tondthebestvaluefortheoperationalfrequencyandthecurrentbottomand
seaconditions.
TheES70willnowshowyouadepthvaluethatisshallowerthantheactualdepth.
4ObservethetruedepthontheOlexsystem.
Thedifferencebetweenthetwodepthsindicatetheheightoftheseagrass.
5ClickOKtosavethecurrentsettingsandclosethedialog.
Sizedistribution,biomassandshdensity
Ifyouusea“splitbeam”transduceronyourES70,itwillyouprovideyouwith
informationaboutthesizedistributionanddensityoftheshbeneaththehull.
Topics
•Howtomonitortheshsizedistributiononpage93
•Howtoadjusttheshlengthforcorrectcalculationsonpage94
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