Garmin gtn 625 GPS Receiver User Manual


 
16-18
Garmin GTN 625/635/650 Pilot’s Guide
190-01004-03 Rev. B
Foreword
Getting
Started
Xpdr Ctrl
Com/Nav
FPL
Direct-To
Proc
Wpt Info
Map
Traffic
Terrain
Weather
Nearest
Music
Utilities
System
Messages
Symbols
Appendix
Index
Note 1: There are several reference datums that waypoints can be surveyed against.
TSO-C146 normally requires that all waypoints be referenced to the WGS84
datum, but allows for navigation to waypoints that are not referenced to the
WGS84 datum so long as the pilot is notified. Certain waypoints in the navigation
database are not referenced to the WGS84 datum, or their reference datum is
unknown. If this is the case, this message is displayed. Garmin cannot determine
exactly how close the non-WGS84 referenced waypoint will be to the WGS84
datum that the GTN uses. Typically, the distance is within two nautical miles. The
majority of non-WGS84 waypoints are located outside of the United States.