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5-2
GDL 88 ADS-B Transceiver Pilot’s Guide
190-01122-03 Rev. A
WARNING: Do not use the indicated data link weather product age to
determine the age of the weather information shown by the data link weather
product. Due to time delays inherent in gathering and processing weather
data for data link transmission, the weather information shown by the data
link weather product may be significantly older than the indicated weather
product age.
5.1 FIS-B NEXRAD
WSR-88DweathersurveillanceradarorNEXRAD(NEXtgenerationRADar)is
a Doppler radar system that has greatly improved the detection of meteorological
events such as thunderstorms, tornadoes, and hurricanes. An extensive network
ofNEXRADstationsprovidesalmostcompleteradarcoverageofthecontinental
UnitedStates,Alaska,andHawaii.TheunobstructedrangeofeachNEXRADis
124 nautical miles.
TheFIS-BFunctionisagraphicweather display capable of displaying graphical
weatherinformationonUATequippedinstallations.Graphicaldataisoverlaidon
the map indicating the rainfall detected by ground based radar for a specific area.
Colorsareusedto identifythe differentNEXRADecho intensities(reectivity)
measured in dBZ (decibels of Z). “Reectivity” (designated by the letter Z) is
theamountoftransmittedpowerreturnedtotheradarreceiver.ThedBZvalues
increase as returned signal strength increases. Precipitation intensity is displayed
usingcolorscorrespondingtothedBZvalues.Anexampleofhowprecipitation
data is color coded follows:
Figure 5-1 Sample FIS-B Weather Precipitation Legend