A range image for micro UAV (unmanned air vehicle) collision avoidance is derived by processing a sequence of conventional
images from a single camera on board the UAV. The range image will warn of looming collisions immediately ahead
and also provide the 3-D situational awareness over a wide field of view needed for semi-autonomous or autonomous
operation of the UAV. This single-camera technique is potentially applicable for other robotic vehicles that may not be
large enough for two-camera stereo. The range image is generated by tracking the motion of scene detail along optic flow
lines. Performance is estimated in terms of the minimum and maximum ranges of scene detail that can be sensed as a function
of its position within the field of view.