Raymarine gS Series - 21.5 Radar range and image quality

21.4Radarcontextmenu
Theradarapplicationincludesacontextmenuwhich
providespositionaldataandmenuitems.
Thecontextmenuprovidesthefollowingpositional
dataforthecursorlocationinrelationtoyourvessel:
•Latitude
•Longitude
•Range
•Bearing
Thecontextmenualsoprovidethefollowingmenu
items:
•AcquireTarget
•PlaceVRM/EBL
•PlaceWaypointAtCursor
•Slewthermalcamera(Onlyavailablewhen
thermalcameraisconnectedandoperating.)
Accessingthecontextmenu
Youcanaccessthecontextmenubyfollowingthe
stepsbelow.
1.Non-touchscreenandHybridTouchdisplays:
i.Selectingalocation,objectortargeton-screen
andpressingtheOkbutton.
2.HybridT ouchandT ouchonlydisplays:
i.Selectinganobjectortargeton-screen.
ii.Selectingandholdingonalocationon-screen.
21.5Radarrangeandimagequality
Radarimagequality
Anumberoffactorscanaffectthequalityofaradar
image,includingechoes,seaclutter,andother
interference.
Notallradarechoesareproducedbyvalidtargets.
Spuriousormissingechoesmaybecausedby:
•Sidelobes.
•Indirectechoes.
•Multipleechoes.
•Blindsectors.
•Sea,rain,orsnowclutter.
•Interference.
Throughobservation,practice,andexperience,you
cangenerallydetecttheseconditionsveryquickly
andusetheradarcontrolstominimizethem.
SideLobes
Sidelobepatternsareproducedbysmallamountsof
energyfromthetransmittedpulsesthatareradiated
outsidethenarrowmainbeam.Theeffectsofside
lobesaremostnoticeablewithtargetsatshort
ranges(normallybelow3nm),andinparticularwith
largerobjects.Sidelobeechoesformeitherarcson
theradarscreensimilartorangerings,oraseriesof
echoesformingabrokenarc.
D1638-5
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ItemDescription
1Mainlobe
2
Sidelobes
3Antenna
4Arc
5
Trueecho
6
Sideechoes
IndirectEchoes
Thereareseveraltypesofindirectechoesorghost
images.Thesesometimeshavetheappearanceof
trueechoes,butingeneraltheyareintermittentand
poorlydened.
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gSSeries