System for precise rotational and positional tracking

1. A system for tracking a movable structure, comprising:

at least one actively emissive fiducial;

at least one video camera;

wherein either the camera or the fiducial is mounted on the movable structure, so that the camera can capture an image of the fiducial as the structure moves;

means for capturing the image from the video camera;

means for determining the location of the fiducial in the captured image, comprising means for resolving the energy received from the active fiducial separately in a plurality of separate areas of a captured video frame, means for comparing the resolved energy to a predetermined energy threshold to find areas with energies above the threshold, and means for resolving the centroid of a larger area of the captured video frame comprised of a separate area with an energy above the threshold and a plurality of contiguous separate areas; and

means, responsive to the means for determining, for resolving the heading of the movable structure.

2. The system of claim 1 further comprising means, responsive to the means for determining, for also determining the location of the movable structure.

3. The system of claim 1 wherein the means for resolving the heading comprises means for comparing captured images over time.

4. The system of claim 1 further comprising means for correcting the captured image for lens distortion.

5. The system of claim 1 wherein the camera is linear.

6. The system of claim 1 further comprising a video display for displaying an image.

7. The system of claim 6 further comprising means for creating computer generated graphics.

8. The system of claim 7 further comprising means for mixing the captured video image and the computer generated graphics, and displaying them together on the video display as an augmented reality image.

9. The system of claim 8 wherein the displayed captured image is taken with a second video camera.

10. The system of claim 1 wherein the fiducial comprises a lamp and a Fresnel lens for capturing and focusing light from the lamp.

11. The system of claim 10 wherein the fiducial further comprises an enclosure for enclosing the lamp, and holding and shading the lens.

12. The system of claim 10 wherein the lamp is directional.

13. The system of claim 10 wherein the lamp filament is located at the focal point of the lens.

14. A system for tracking a movable structure, comprising:

at least one actively emissive fiducial;

at least one linear video camera;

wherein either the camera or the fiducial is mounted on the movable structure, so that the camera can capture an image of the fiducial as the structure moves;

means for capturing the image from the video camera;

means for determining the location of the fiducial in the captured image, comprising means for resolving the energy received from the active fiducial separately in a plurality of separate areas of a captured video frame, means for comparing the resolved energy to a predetermined energy threshold to find areas with energies above the threshold, and means for resolving the centroid of a larger area of the captured video frame comprised of a separate area with an energy above the threshold and a plurality of contiguous separate areas; and

means, responsive to the means for determining, for resolving the heading of the movable structure, the means for resolving the heading comprising means for comparing captured images over time.

15. A system for tracking a movable structure, comprising:

at least one actively emissive fiducial;

at least one linear video camera;

wherein either the camera or the fiducial is mounted on the movable structure, so that the camera can capture an image of the fiducial as the structure moves;

means for capturing the image from the video camera;

means for determining the location of the fiducial in the captured image, comprising means for resolving the energy received from the active fiducial separately in a plurality of separate areas of a captured video frame, means for comparing the resolved energy to a predetermined energy threshold to find areas with energies above the threshold, and means for resolving the centroid of a larger area of the captured video frame comprised of a separate area with an energy above the threshold and a plurality of contiguous separate areas;

means, responsive to the means for determining, for resolving the heading of the movable structure, the means for resolving the heading comprising means for comparing captured images over time;

a video display for displaying an image;

means for creating computer generated graphics; and

means for mixing the captured video image and the computer generated graphics, and displaying them together on the video display as an augmented reality image.