Garmin GDL 69A Pilot's Manual Addendum

Also see for GDL 69: Pilot's guide addendum Activation Instructions Pilot's guide Activation Instructions Pilot's guide addendum

Contents

Garmin GDL 69A Pilot's Manual Addendum Manual pdf 18 page image

14Part Two: Section 2XM Weatheralmost complete coverage of the continental UnitedStates, Alaska, and Hawaii. The unobstructed range ofeach NEXRAD is up to 250 nautical miles.When enabled, composite data from all theNEXRAD radar sites in the United States is shown.This data are composed of the maximum reflectivityfrom the individual radar sweeps. The display is color-coded to indicate the weather level severity. Informa-tion about with sites are operational or off-line is alsoavailable.To display NEXRAD weather on the Map page:1. With the Map page (the second page of theNAV page group) displayed, press the MENUkey. The Page Menu for the Map page appears.NEXRAD is also available on the Nav 1 pageof the 500W series.2. Turn the large right knob to highlight “Dis-play NEXRAD,” and then press ENT. (If “HideNEXRAD” appears, NEXRAD radar data arealready enabled; just press MENU again toexit the Page Menu.)To display NEXRAD weather on the XM Weatherpage:1. With the XM Weather page (the third page ofthe NAV page group) displayed, look at theupper left corner of the page. Under the pagetitle (“XM Weather”) either “NEXRAD” oranother weather product appears. If the wordis “NEXRAD,” do nothing; NEXRAD weather isalready being displayed.2. If the word in the upper left corner of thepage is another weather product (rather than“NEXRAD”), press the small right (CRSR)knob to highlight that word. Then turn thesmall right knob to change to “NEXRAD.”3. Press the small right knob again to bringdown the cursor (that is, to stop the blinkinghighlighting of “NEXRAD”) and retain theselection.NEXRAD IntensityColors are used to identify the different NEXRADecho intensities (reflectivity) measured in dBZ (deci-bels of Z). “Reflectivity” is the amount of transmittedpower returned to the radar receiver. Reflectivity(designated by the letter Z) covers a wide range ofsignals (from very weak to very strong). So, a moreconvenient number for calculations and comparison, adecibel (or logarithmic) scale (dBZ), is used. The dBZvalues increase as the strength of the signal returnedto the radar increases. There are seven gradations forrain, two gradations for mixed rain and snow, and twogradations for snow.190-00356-30 Rev C