Azimuth Reference azRefType UKOOA 1.0 MAGNETIC The azimuths in the survey are referenced to magnetic north. GRID The azimuths in the survey are referenced to grid north, which is the direction of the northing axis. TRUE The azimuths in the survey are referenced to true north, which is the direction of the meridian line. INCLINATION ONLY Unknown meaning UNKNOWN The direction of the north reference is not known.