ObjectiveMulti-missile collaborative guidance has become the main form of modern battlefield, and efficient information transmission between missiles is particularly important. When using lasers as carriers for information transmission between missiles, the presence of atmospheric turbulence has a serious impact on the Pointing, Acquisition and Tracking system. Therefore, it is urgent to propose a beacon positioning method that can accurately calculate the center position of the light spot under different atmospheric turbulence conditions, meeting the stability requirements of inter-missile laser communication. This paper proposes a beacon light spot positioning method based on optical flow features, which has high positioning accuracy and stability.
MethodsThe flowchart of the center position positioning method proposed by this paper is shown in
Fig.1. The collected light spot image is converted into a grayscale image, and the corner detection method is used to select feature points, then the feature points are further screened by maximum suppression, and sparse optical flow method is used to track the screened feature points to obtain their inter frame offset. Calculate the average inter frame offset of all feature points to approximate the center position offset of the light spot, iteratively compensate it to the initial center coordinates of the light spot, and achieve continuous prediction of the center position of the light spot.
Results and DiscussionsSelect continuous images of light spots under different intensities of atmospheric turbulence, light spot center position positioning methods based on optical flow features and grayscale centroid method were used for continuous positioning. The average positioning errors and variances in
x-direction and
y-direction were compared accordingly. The comparison results under weak turbulence conditions are shown in
Tab.1, results under moderate turbulence conditions are shown in
Tab.2, and results under strong turbulence conditions are shown in
Tab.3. The results indicate that our method has high positioning accuracy and stability under various intensities of atmospheric turbulence.
ConclusionsA beacon light spot positioning method based on optical flow characteristics has been proposed in this paper, this method is simple to implement and has high accuracy. Continuous spot images under weak, medium, and strong atmospheric turbulence conditions were collected by 11.16 km urban link optical communication experiment, proving that our method has high positioning accuracy under different atmospheric turbulence conditions, which provides an experimental basis for the study of 10 km level laser communication between missiles and has practical reference value.