Undersea LiDAR imager for unobtrusive and eye safe marine wildlife detection and classification
Marine hydrokinetic (MHK) projects are composed of undersea power generating equipment that converts energy of waves, tides, or ocean currents into electricity. Of primary interest when deploying MHK devices is gaining an understanding of potential harmful interactions between marine animals and equipment at proposed development sites. Therefore, a high priority regulatory expectation exists to observe marine life interaction with such devices. Underwater video observation of MHK scenes is typically accomplished with optical or acoustical cameras. Traditional optical cameras are most effective when significant ambient light is present and in low turbidity. Even the most sophisticated commercially-available underwater camera technologies require artificial white light to illuminate low light scenes. This approach is not desirable for MHK monitoring because artificial light can alter the behavior of the animals being monitored. For example, it has been observed that marine life are attracted to light-emitting sources of wavelengths within their visual light frequency range. However, unlike active acoustic solutions, the primary advantage of using optical approaches is high resolution contrasted scene descriptions essential for object classification and detailed observations. Because red laser illuminators can be configured below the maximum permissible exposure (MPE) limit for humans, which is conservative with regard to marine wildlife due to the lower visual acuity of the eye, and also beyond the wavelength range that is visible to marine wildlife, such systems can be designed to be eye-safe, unobtrusive, and allow for 24/7 operations.