INTERCEPT PROCEDURES TEXTBOOK
The magnetic bearing call or bogey bearing (BB) call, provided by the GCI controller, is the
bearing from the fighter to the bogey, independent of fighter or bogey heading.
The relative azimuth (angle off), however, changes as a result of the fighter's turn and
changes in the same amount but in the opposite direction of the turn.
To illustrate this, look through a window directly in front and see an object 45º right. Now
turn your gaze 90º to the right with the window still directly in front. Before turning, the object
appeared 45º right (angle off) and after turning 90º right the object appeared to move left 90º to
45º left (angle off). Note: The position in the room has not changed, but the angle to the object
The magnetic bearing call will not change instantaneously with a change in
fighter heading, but will change as the fighter travels through space.