Deep Seabed Images Produced by the Underwater UV Laser Scanner Mounted on an Underwater Vehicle in Deep-Water Tests

In recent years, underwater laser scanners have been attracting attention as one of useful technologies for visualizing the deep-seabed. The deep-seabed images are produced by detecting the reflection of lasers which are irradiated toward the seabed. In order to detect unprecedented seabed reflection characteristics, we are developing a new underwater laser scanner that uses an ultraviolet (UV) laser, which is an invisible wavelength, as a laser source for the underwater laser scanner. The laser source with a near-ultraviolet wavelength of 355 nm is used, in order to generate seabed images different from those of conventional underwater laser scanners with visible wavelength lasers. A deep-sea demonstrator of the underwater UV-laser scanner was developed and mounted on an underwater vehicle for deep-water tests. As the results, various reflection characteristics of the deep-seabed against the UV-laser were detected, and deep-seabed areas were visualized in detail.