Cockpit Reference Guide

Garmin G1000 Pilot’s Guide for the Piper PA-46 Meridian
190-00763-02 Rev. A310
HAZARD AVOIDANCE
SYSTEM
OVERVIEW
FLIGHT
INSTRUMENTS
EICAS
AUDIO PANEL
& CNS
FLIGHT
MANAGEMENT
HAZARD
AVOIDANCE
AFCS
ADDITIONAL
FEATURES
APPENDICESINDEX
SYSTEM
OVERVIEW
FLIGHT
INSTRUMENTS
EICAS
AUDIO PANEL
& CNS
FLIGHT
MANAGEMENT
HAZARD
AVOIDANCE
AFCS
ADDITIONAL
FEATURES
APPENDICESINDEX
ThedifferentNEXRADechointensitiesaremeasuredindecibels(dB)relativetoreectivity(Z).NEXRAD
measurestheradarreectivityratio,ortheenergyreected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:
•NEXRADbasereectivitydoesnotprovidesufcientinformationtodeterminecloudlayersorprecipitation
characteristics.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 NEXRAD Data - Zoomed
Each block
covers an Area
of 4 sq. km