An apparatus and method is disclosed for enabling accurate registration of
virtual information upon real objects in selected environments from the
perspective of a moveable observation platform having a position and an
orientation within an observation space positioned within the
environment, the position and orientation defining the registration of
the virtual information within the observation space within the
environment, which may comprise: a plurality of at least three tracking
fiducials selectively each respectively located in fixed predetermined
locations in the observation space; the observation platform including a
position sensor apparatus adapted to sense an estimated position of the
observation platform in the observation space and a heading sensor
apparatus adapted to sense an estimated heading of the observation
platform within the observation space; the observation platform further
including a wide view fiducial detection apparatus mounted on the
observation platform and adapted to detect the relative direction from
the observation platform to each of the plurality of tracking fiducials,
a heading error detection apparatus adapted to detect the difference
between the estimated heading and the present heading based upon the
observed relative directions to the respective tracking fiducials, and
forming a corrected heading from the estimated heading and the detected
heading error.