Development of long range color imaging for wide area 3D reconstructions of the seafloor

Abstract

3D visual mapping of the seafloor has found applications ranging from environment monitoring and survey of marine minerals to underwater archeology and inspection of modern man-made structures. However, the attenuation of light is significantly more pronounced in water than in air or in space, and so in order to obtain underwater images in color, it is typically necessary to be within 2 to 3 m of the seafloor. In addition to the high risk of collision when operating underwater vehicles at such low altitudes, the limited area of the seafloor covered in each image means large area surveys require a huge investment of time. In this research, we aim to increase the efficiency of mapping large areas of the seafloor by developing an underwater imaging system that can take color images at ranges of up to 13 m, so that each image can cover a larger area, together with the necessary algorithms to automatically process the data it obtains. The system was deployed to map artificial hydrothermal vents in Iheya North Knoll using the ROV Hyper-Dolphin in October 2012. In this paper, we describe the instrument and the methods used to process the data it obtains, and present wide area 3D reconstructions of habitats surrounding artificial hydrothermal vents.

Optical Sensors and Methods for Underwater 3D Reconstruction

“…Therefore, there is enough contrast to detect the laser line. In [ 77 , 85 , 86 ], a similar system, called SeaXerocks (3D mapping device), is mounted on the ROV Hyper-Dolphin. With this system, the authors perform 3D reconstructions in real intervention scenarios, such as in hydrothermal sites and shipwrecks.…”

Next-Generation Optical Sensing Technologies for Exploring Ocean Worlds—NASA FluidCam, MiDAR, and NeMO-Net

“…However, significant progress has been made in the past decade with underwater remotely operated or autonomous underwater vehicles (ROVs and AUVs) (Roberts et al, 2010), unmanned surface vehicles (USVs) (Mordy et al, 2017), and profiling floats (Roemmich and Gilson, 2009) to characterize the seafloor, ocean surface, and ocean column over large geographic areas. Recently, three-dimensional photogrammetry, active acoustical methods, and in situ water column measurements have been used with remarkable effectiveness on such platforms to narrow the gap in observational capacity between terrestrial and aquatic systems, revealing mesophotic, and deep sea habitats with unexpected biodiversity and ecological complexity (Pizarro et al, 2004;Bodenmann et al, 2013).…”

Guidance method of underwater vehicle for rugged seafloor observation in close proximity

“…It is anticipated that through collaborative interactions among AUVs, efficient marine surveys can be conducted. There have been successful instances where AUVs conducted wide‐ranging underwater optical imaging without direct support from a ship (Bodenmann et al, 2023). In this research, a long‐range capable AUV and satellite communication are utilized to successfully accomplish extended missions without the need for close human supervision or support.…”