Underwater laser positioning of targets outside the field of view based on a binocular vision.

An underwater laser positioning scheme based on a binocular camera is introduced. In spite of the scattering, the underwater laser light path can be clearly captured by a camera within an appropriate range depending on the water turbidity. For an emitting laser with a fixed position, the three-dimensional information of the laser source can be calculated from the beam images captured by a binocular camera, even if the laser is out of the camera's field of view (FOV). This method can break through the FOV limitation of traditional camera positioning and perform a 3D spatial positioning for the target even outside the FOV of the camera. We simulate and analyze the scattering light imaging and find that the laser propagation direction can be recognized from the scattering image. The experimental results show that the proposed underwater positioning scheme achieves an average 3D positioning error of 5.53 cm within a range of 5 m when the underwater attenuation is 0.325 .