Off-axis laser beam imaging and characterization with two cameras

Off-axis scattering of laser beams propagating in the atmosphere has been imaged by two separated cameras. We give a theoretical analysis and report experiments that show how these images can be used to reconstruct the position and orientation of the beam relative to the cameras. The information from a single image of the beam only determines the beam within a plane. However, the intersection of these planes of ambiguity using images from two cameras can determine the beam uniquely. When the two planes are nearly parallel, an independent method based on the relative radiance at each camera can be used to determine the beam direction.