6.10 Position Referencing

6.10.2 Define: 

(a) Ground Position;

The Ground Position is the position on the ground directly beneath the aircraft.

(b) Dead Reckoning (DR) Position;

A DR Position is the assumed ground position based on calculation.

The information used to arrive at the D.R. position is never totally accurate.

(c) Fix;

A Fix is the position of an aircraft determined by any method other than by direct observation.