Raymarine E90W - Page 122

ItemDescription
6
Ship’sHeadingMarker(SHM)
7
Ship’sposition
8MotionMode
9Radarscannerstatus
10Waypoint
11Rangeringspacing
Typically,yourvessel’spositionisatthecenterofthedisplay,and
itsdeadaheadbearingisindicatedbyaverticalheadingline,known
astheShip’sHeadingMarker(SHM).
On-screentargetsmaybelarge,small,brightorfaint,dependingon
thesizeoftheobject,itsorientationandsurface.Ifusinganon-HD
digitalradomescanner,strongesttargetreturnsaredisplayedin
yellowwithweakerreturnsin2shadesofblue.IfusinganHDor
SuperHDdigitalradarscanner,strongertargetreturnsshowas
differentcolorsfromarangeof256colors,providingbetterclarity.
Beawarethatthesizeofatargetonscreenisdependentonmany
factorsandmaynotnecessarilybeproportionaltoitsphysicalsize.
Nearbyobjectsmayappeartobethesamesizeasdistantlarger
objects.
Withexperience,theapproximatesizeofdifferentobjectscanbe
determinedbytherelativesizeandbrightnessoftheechoes.
Youshouldbearinmindthatthesizeofeachon-screentargetis
affectedby:
•Thephysicalsizeofthereectingobject.
•Thematerialfromwhichtheobjectismade.Metallicsurfaces
reectsignalsbetterthannon-metallicsurfaces.
•Verticalobjectssuchascliffsreectsignalsbetterthansloping
objectssuchassandbanks.
•Highcoastlinesandmountainouscoastalregionscanbeobserved
atlongerradarranges.Therefore,therstsightoflandmaybea
mountainseveralmilesinlandfromthecoastline.Althoughthe
coastlinemaybemuchnearer,itmaynotappearontheradar
untilthevesselisclosertoshore.
•Sometargets,suchasbuoysandsmallboats,canbedifcult
todiscern,becausetheydonotpresentaconsistentreecting
surfaceastheybobandtossaboutinthewaves.Consequently
theseechoestendtofadeandbrighten,andattimesdisappear
momentarily.
•Buoysandsmallboatsoftenresembleeachother,butboatscan
oftenbedistinguishedbytheirmotion.
Note:AGPSreceiverandafastheadingsensorarerequired
forMARPAoperation,andtomaximizeradar/chartoverlay
performance.
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E-SeriesWidescreenUserreference