Vertical Water Column Survey in the Gulf of Mexico Using Autonomous Underwater Vehicle SOTAB-I

Abstract

Oil spills caused by accidents from oil tankers and blowouts of oil and gas from offshore platforms cause tremendous damage to the environment as well as to marine and human life. To prevent oil and gas accidentally released from deep water from spreading and causing further damage over time to the environment, early detection and monitoring systems can be deployed to the area where underwater releases of oil and gas first occurred. Monitoring systems can provide a rapid inspection of the area by detecting chemical substances and collecting oceanography data necessary for enhancing the accuracy of simulation of behavior of oil and gas. An autonomous underwater vehicle (AUV) called the Spilled Oil and Gas Tracking Autonomous Buoy system (SOTAB-I) is being developed to perform onsite measurements of oceanographic data as well as dissolved chemical substances using underwater mass spectrometry. The scope of this paper is limited to the surveying abilities of SOTAB-I in shallow water, although it also has functions for surveying in deep water. The experiment results obtained during the early deployments of SOTAB-I in the shallow water of the Gulf of Mexico in the United States are provided. Oceanographic data, such as the water column distribution of temperature, salinity, and density, as well as the dissolution of chemical substances were measured. In addition, a high-resolution water current profile was obtainable near the seabed. <def-list> Nomenclature <def-item> <term>ADCP</term> <def> acoustic Doppler current profiler </def> </def-item> <def-item> <term>AUV</term> <def> autonomous underwater vehicle </def> </def-item> <def-item> <term>BTX</term> <def> benzene-toluene-xylenes </def> </def-item> <def-item> <term>CTD</term> <def> conductivity-temperature-depth </def> </def-item> <def-item> <term>DVL</term> <def> Doppler velocity logger </def> </def-item> <def-item> <term>GPS</term> <def> global positioning system </def> </def-item> <def-item> <term>MIMS</term> <def> membrane introduction mass spectrometry </def> </def-item> <def-item> <term>PID</term> <def> proportional-integral-derivative </def> </def-item> <def-item> <term>PSU</term> <def> practical salinity units </def> </def-item> <def-item> <term>RMSE</term> <def> root mean square error </def> </def-item> <def-item> <term>UMS</term> <def> underwater mass spectrometer </def> </def-item> <def-item> <term>USBL</term> <def> ultra-short base line </def> </def-item> <def-item> <term>VOC</term> <def> volatile organic compound </def> </def-item> <def-item> <term>VRU</term> <def> vertical reference unit </def> </def-item> </def-list>

Particle Filter based Autonomous Underwater Vehicle Navigation System aided thru acoustic communication ranging

“…The inertial navigation computation starts with the transformation of the vehicle acceleration measurements vector from the b-frame to the n-frame through a Direction Cosines Matrix (DCM) : (1) where;…”

“…Autonomous Underwater Vehicles (AUVs) are platforms suitable for a wide variety of applications in several fields in the marine environment with economic and operational advantages [1], [2] and [3].…”

A Review of the Emerging Field of Underwater Mass Spectrometry

“…In 2007, researchers that transferred from USF to SRI International (SRI) continued developments and deployments of UMS systems. Since the Deepwater Horizon incident in 2010, a major focus of SRI's UMS development and deployments has been on the detection and mapping of light hydrocarbons (methane, ethane, propane, and butane) from natural hydrocarbon seeps and leaking oil and gas underwater assets (Short et al, 2011(Short et al, , 2013(Short et al, , 2015Choyekh et al, 2015). The current generation of SRI instruments has a heated PDMS membrane supported by a sintered Hastelloy C rod (Bell et al, 2007), a more efficient linear quadrupole mass analyzer, and more compact vacuum pumps (Short et al, 2011(Short et al, , 2013(Short et al, , 2015.…”

Ictiobot-40 a low cost AUV platform for acoustic imaging surveying

“…In addition, due to the less user intervention, operational costs are reduced [1] and [2]. The fields in which AUVs are used include; hydrographic and scientific survey, offshore industry and defense [3], [4], [5] [6] [7] and [8]. Due to the extreme nature of the underwater environment, that includes high pressures, corrosive effects of seawater and the possibility of damage by bad sea state or collisions, the reliability of AUVs is a topic of interest to avoid the loss of high cost equipment [9].…”