The manned submersible as an effective sampling and imaging platform

Abstract

Remotely operated vehicles (ROVs), tow bodies and autonomous undersea vehicles (AUVs) are increasingly being used as platforms for underwater measuring, collecting and imaging. However, there are tasks for which a free-swimming, manned vehicle is a cost-effective platform. The effectiveness of an in-situ operator, rather than one remotely located from the sampling or measurement platform, is primarily due to two factors: intelligent vision and adaptive decision making. In spite of the advances made in stereo-vision systems and telepresence, the on-site human eye often outperforms other vision systems. The presence of an operator on board the vehicle also allows decisions to be made rapidly, or an experiment to be modified when conditions are not as anticipated. This paper describes several successful, ongoing projects utilizing Harbor Branch Oceanographic Institution's (HBOI) manned submersibles. One project involved imaging natural and man-made objects near the ocean floor using a laser-line-scanning (LLS) system equipped with multiple receivers. This system was interfaced to the Research Submersible CLELIA and was employed on five missions during 1996. Spectacular high-resolution black and white, fluorescence and color images were obtained. Inter-disciplinary research cruises to cold-seep regions of the Gulf of Mexico with the JOHNSON-SEA-LINK (J-S-L) submersibles allow multi-parameter probing of brine pools and specialized collection of biological, geological and geochemical samples. For example, methane ice samples are removed from deposits on the ocean floor at a depth of 2000 ft. and transported under pressure to a laboratory on board the support vessel for analysis.