Garmin G1000 PDAs & Smartphones User Manual


 
Garmin G1000 Pilot’s Guide for Cessna Nav III
190-00498-07 Rev. A
SYSTEM
OVERVIEW
FLIGHT
INSTRUMENTS
EIS
AUDIO PANEL
& CNS
FLIGHT
MANAGEMENT
HAZARD
AVOIDANCE
AFCS
ADDITIONAL
FEATURES
APPENDICESINDEX
290
HAZARD AVOIDANCE
neXRaD limitatiOns
NEXRADradarimagesmayhavecertainlimitations:
•NEXRADbasereectivitydoesnotprovidesufcientinformationtodeterminecloudlayersorprecipitation
characteristics(wethailvs.rain).Forexample,itisnotpossibletodistinguishbetweenwetsnow,wet
hail, and rain.
•NEXRADbasereectivityissampledattheminimumantennaelevationangle.AnindividualNEXRAD
sitecannotdepicthighaltitudestormsatcloseranges.Ithasnoinformationaboutstormsdirectlyover
the site.
•Whenzoomedintoarangeof30nm,eachsquareblockonthedisplayrepresentsanareaoffoursquare
kilometers.Theintensitylevelreectedbyeachsquarerepresentsthe
highest
levelofNEXRADdata
sampledwithinthearea(Figure6-12).
•Unknownprecipitationoccurringbelow52ºNisdisplayedasrain.
Figure 6-12 NEXRAD Data - Zoomed
Block Area is 4 km
2
ThefollowingmaycauseabnormalitiesindisplayedNEXRADradarimages:
•Groundclutter
•Strobesandspuriousradardata
•Sunstrobes(whentheradarantennapointsdirectlyatthesun)
•Interferencefrombuildingsormountains,whichmaycauseshadows
•Metallicdustfrommilitaryaircraft,whichcancausealterationsinradarscans