User manual

SimradES70
Deningmaximumandminimumdepths
WhenyouusetheES70itisveryimportantthatitdetectsand“locks”onthecorrect
depth.Normallythiswillhappenautomatically.However,certainconditions(suchas
noiseorairunderthehull),ortheappearanceoflargeschoolsofsh,may“fool”the
sounder.Whenthebottomisundetectedyouwillread0.00metersdepth.
InordertoguidetheES70tolocatethecorrectdepth,youmaysometimesndituseful
tofollowthisprocedure.
Note
Ifyousetmaximumdepthtoavalueidenticalorsmallerthantheminimumvalue,the
bottomdetectionalgorithmwillbedisabled.TheES70willthennotbeabletodetect
thebottomatall,andthedisplayeddepthwillbe0.00m
1ClicktheActiveicon.
ThisiconislocatedundertheMainmenu.ItisusedtoopentheActive
menu.
→Activemenuonpage153
2OntheActivemenu,clickBottomDetectortoopentheBottomDetectordialog.
ThepurposeoftheBottomDetectordialogistodenetheupperandlowerdepth
limitsmostlikelytobeusedduringtheES70operation.Inthisdialog,youcanalso
modifythesettingforBottomBacksteptochangethebottomdetectionrelativeto
thebottomecho.
→BottomDetectoronpage232
3EnteraMinimumDepth.
Thissettingeliminatesallunwantedbottomdetectionsfromthetransducersurface
anddowntothedeneddepth.
4EnteraMaximumDepth.
Setthisdepthtoapproximately50%morethantheexpecteddepth.IftheES70
shouldloosebottomdetectionduetoairorotherdisturbances,itwilltrytorelocate
thedepthwithintheminimumandmaximumdepthsyouhavedened.Donot
exaggerate.Ifyouforexampleenter5000metersandthebottomtrackislost,the
ES70willsearchtheentiredepthfornewbottomlock.Thiswilltakealotoftime.
5ClickOKtosavethecurrentsettingsandclosethedialog.
Adjustingthebottomdetectiontondatsh
TheES70providestheBottomBackstepparameterintheBottomDetectordialog.Y ou
canusethisparametertoenhancethedetectionofsole,ounderandsimilarspecies.
→Bottomslopesonpage288
72
338106/C