Installation manual
Echosoundertheory
Whenyouusebottomexpansion,thewatersurfaceisnotthereferenceanylonger,but
thebottomis.Itisalways0.Thatmeansthatthebottominthisechogramwillalwaysbe
at,eventhoughitmayvaryintheupperechogram.Tochooseaverticaldepthrangefor
thebottomexpansion,setRangetoapositivevalue.Thisisthetotalverticalrangeof
theechogram.Then,setStartRangetoanegativevalue.Thisistheechogram’sstart
heightabovethebottom.Inthisechogrampositivedepthisbelowthebottom,while
negativedepthisabove.
Typicalsettingsmaybe:
•Range=15m
•Startrange=–10m
Thisprovidesyouwitha15metershighphasedareastartingat10metersabovethe
bottomto5metersbelowit.
Example19StartRangeandRangeinbottomrelatedechogram
Inabottomechogram,settheStartRangevalueto–5meters.Thiswill
maketheechogramstartfrom5metersabovethebottom.SetRangetothe
5metersplus10=15meters.Theechogramwillnowshowtheareafrom
5metersabovethedepth,anddownto10meters“below”thebottom.The
bottomcontourwillappearasaatline.
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