Pilot's Guide

Garmin G1000 Pilot’s Guide for the Hawker Beechcraft C90A/GT/GTi
190-00663-02 Rev. B304
HAZARD AVOIDANCE
Displaying NEXRAD weather information:
1) Select the MAP Softkey (for the PFD Inset Map, press the INSET Softkey). This step is not necessary on the
Weather Data Link (XM) Page.
2) Select the NEXRAD Softkey.
ThesystemshowsacompositeimagefromalltheNEXRADradarsitesintheUnitedStates.Thisinformation
showsthemaximumreectivityfromtheindividualradarsweeps.Thedisplayoftheinformationiscolor-
codedtoindicatetheweather severitylevel.Allweatherproductlegendscanbeviewedon theWeather
DataLink(XM)Page.FortheNEXRADlegend(Figure6-11),selectthe LEGENDSoftkeywhenNEXRAD
is enabled for display.
No Radar Coverage
Figure 6-11 NEXRAD Data with Legend
ThedisplayofnoradarcoverageisalwaysactivewheneitherNEXRADorEchoTopsisselected.Areas
whereNEXRADradarcoverageandEchoTopsinformationisnotcurrentlyavailableorisnotbeingcollected
are indicated in gray shade of purple.
reflectivity
Reectivityistheamountoftransmittedpowerreturnedtotheradarreceiver.ColorsontheNEXRAD
displayaredirectlycorrelativetothelevelofdetectedreectivity.Reectivityasitrelatestohazardous
weather can be very complex.
Theroleofradarisessentiallytodetectmoistureintheatmosphere.Simplyput,certaintypesofweather
reectradarbetterthanothers.Theintensityofaradarreectionisnotnecessarilyanindicationofthe
weatherhazardlevel.Forinstance,wethailreturnsastrongradarreection,whiledryhaildoesnot.Both
wet and dry hail can be extremely hazardous.
ThedifferentNEXRADechointensitiesaremeasuredindecibels(dB)relativetoreectivity(Z).NEXRAD
measures the radar reflectivity ratio, or the energy reflected backto theradarreceiver( designated by the
letterZ) .ThevalueofZincreasesasthereturnedsignalstrengthincreases.
neXraD limitations
NEXRADradarimagesmayhavecertainlimitations: