Morphological filter algorithm to improve positioning accuracy of multi-laser convergent spot center

In a laser command transmission application, many laser diodes with identical features are arranged in matrix to form a combined light source to achieve a bigger coverage area and longer range. Since the image spot emitted from the lattice multi-laser source has multiple energy centers in open space, the opening and closing calculation in the morphological filtering were used to remove the background noise spots, smooth irregular fringe and holes caused by the small spots overlap and interference. With this method, a full boundary similar to that of an actual image could be achieved with a simplified algorithm of segmentation and location. The mean square error for the position accuracy of the spot center is less than 1.2% in repeated measurements. The center of the overlapping spots can be rapidly and accurately located by this method. It provides the necessary accuracy and speed for laser alignment and measurement at long distance.