Garmin G1000H Marine Radio User Manual


  Open as PDF
of 548
 
190-01255-00 Rev. B
Garmin G1000H
™
Pilot’s Guide for the Bell 407GX
295
HAZARD AVOIDANCE
Displaying NEXRAD weather information:
1) Select the MAP Softkey (for the PFD Inset Map, select the INSET Softkey). This step is not necessary on the
Weather Data Link (XM) Page.
2) Select the NEXRAD Softkey.
CompositedatafromalltheNEXRADradarsitesintheUnitedStatesisshown.Thisdataiscomposedof
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selectedfor
display.
No Radar Coverage
Figure 6-11 NEXRAD Data with Legend
Thedisplayof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.
 previous next