Raymarine RAYCHART 420D - Manual (Page 96)

Appendix C: List of abbreviations C-1
Appendix C: List of abbreviations
BDI Bearing Deviation Indicator
BTW Bearing To Waypoint
CDI Course Deviation Indicator
COG Course Over Ground. The actual direction of your vessel’s
movement over the ground.
dGPS Differential Global Positioning System
DTG Distance To Go
EMC Electro-Magnetic Compatibility
ETA Estimated Time of Arrival
GPS Global Positioning System
HDOP Horizontal Dilution Of Precision. The multiplicative factor that
modifies ranging error. It is caused solely by the geometry
between your vessel and your set of satellites.
MOB Man OverBoard
NMEA National Marine Electronics Association (interconnection
standard)
SOG Speed Over Ground. The rate of movement of the vessel over the
ground.
TTG Time To Go
WPT Waypoint
XTE Cross Track Error