Vision-based vehicle navigation system and method

A system for estimating aircraft position on an aerodrome ground surface having a centerline disposed thereon, the system comprising:

• a camera mounted on an aircraft at a preset pitch angle, the camera having a known focal length and operable to capture an image of at least a portion of the aerodrome ground surface including the visible centerline and supply image data representative of the captured image, the visible centerline extending to a vanishing point in the captured image, and at least a portion of the visible centerline in the captured image having a slope and an intercept;
• and
• a processor coupled to receive the image data and operable, upon receipt thereof, to compute:
• the slope and intercept of at least a portion of the centerline,
• a vertical position of the vanishing point,
• a horizontal position of the vanishing point, and
• an estimate of the aircraft position on the aerodrome ground surface from the computed horizontal position of the vanishing point, the known focal length, and the preset pitch angle.

A method of determining vehicle position on a ground surface having a centerline disposed thereon, the method comprising the steps of:

• capturing a current image of the ground surface using a camera having a known focal length and being disposed on a vehicle at a preset pitch angle, the image including the centerline, the centerline extending to a vanishing point in the captured image, and at least a portion of the centerline having a slope and an intercept;
• computing the slope and intercept of at least a portion of the centerline;
• computing a vertical position of the vanishing point;
• computing a horizontal position of the vanishing point;
• computing an estimate of the vehicle position on the ground surface using the computed horizontal and vertical positions of the vanishing point, the known focal length, and the preset pitch angle.