11-53190-01004-03 Rev. P GTN 625/635/650 Pilot’s GuideForewordGettingStartedAudio &Xpdr CtrlCom/NavFPLDirect-ToProcWpt InfoMapTrafficTerrainWeatherNearestServices/MusicUtilitiesSystemMessagesSymbolsAppendixIndex11.4.2.3 NEXRAD AbnormalitiesThere are possible abnormalities regarding displayed NEXRAD images. Some,but not all, causes of abnormal displayed information include:• Ground Clutter• Strobes and spurious radar data• Sun strobes, when the radar antenna points directly at the sun• Military aircraft deploy metallic dust which can cause alterations in radarscans• Interference from buildings or mountains, which may cause shadows• Scheduled maintenance may put a radar off-lineAffected AreasAny area in the continental United States (CONUS) or Alaska where thedistance from ADS-B ground stations, or the combined effect of distance andlow altitude, is sufficiently great may cause poor reception. To find the latestground station coverage, visit faa.gov.Reception will improve in some affected areas as the FAA completes theNextGen ADS-B ground station infrastructure. However, due to line-of-sightbroadcast characteristics, operators with properly installed and functioningequipment may still receive incomplete FIS-B data when signal reception islimited by the distance from ground stations combined with a low altitude.
