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In 2015, the Hanna Shoal region of the Chukchi Sea shallower than the 40 m isobath was withdrawn from outer continental shelf oil and gas exploration, a move the White House noted was designed to protect areas of “critical importance … for marine mammals, other wildlife, and wildlife habitat”. Arctic regions are projected to strongly manifest impacts of an altered climate and subsurface moored continuous...
Development of an autonomous unmanned surface vehicle (USV) that may serve as a mother ship for a small unmanned aerial vehicle (UAV) and a small autonomous underwater vehicle (AUV), in support of surface autonomy in sensing and surveillance missions, is described. The USV development includes implementation of low-level controls, stereovision perception, and a task-oriented high-level planner, which...
The Sensor Hosting Autonomous and Remote Craft (SHARC) Wave Glider is an autonomous, surface vehicle (USV) used to collect and deliver real-time data in remote ocean locations around the world. Liquid Robotics Inc. (LRI) manufactures the Wave Glider for the defense, maritime surveillance, environmental assessment, and oil and gas industries. It is powered by wave energy and supplemented by solar energy...
The presence of high frequency components in dolphin echolocation signals and their possible significance in dolphin sonar is reported here, based on echolocation experiments conducted with several bottlenosed dolphins. Measurements on the animals' sonar capability under varied conditions, including imposed difficulties for target detection are discussed. Blindfolded dolphin test subjects were utilized...
A graphical tool to qualitative analysis of underwater unmanned vehicles and cable-like flexible structures is presented. The software provides a realistic virtual environment where the dynamic behavior of different underwater systems can be studied from numerical simulation to generate animations.
Real-time quality control (qc) of oceanographic data is usually accomplished by testing data points against a variety of conditions to identify the quality of the data. Since 2012, the U.S. Integrated Observing System (U.S IOOS®) Program Office Quality Assurance/Quality Control of Real-Time Oceanographic Data (Qartod) Project has worked with the ocean-observing community both nationally and internationally...
Oceanographic applications increasingly rely on the integration of multivariate data from diverse observational platforms, the coupling of remote sensing and field data being integral to analysis workflows. However, the inherent heterogeneity of in situ datasets and their variable adherence to meta/data standards poses a significant impediment to interoperability and long-term data stewardship. Here...
Tidal power generation has advantages over other renewables in terms of predictability and consistency, but is one of the least tapped sources of clean energy. While historically most tidal power has been generated using large impoundments, recently turbines have been developed to be placed in fast-flowing tidal currents and thus supply electricity from the tides in a cheaper and less environmentally...
The oceans are a tremendous source of clean, renewable energy, yet the majority of this resource is located far from shore and the population centers that could benefit from the generated power. Tidal energy has been harnessed in various ways over the last few centuries, for both mechanical and electrical power generation. Presently, tidal energy is quickly becoming a viable alternative to conventional...
This paper proposes an underwater acoustic Single Carrier Frequency Division Multiplexing (SC-FDM) communication system with a forward error correction to transmit image or movie data packet from deep sea ROV (Remotely operated vehicle) etc. to surface ship. Since the SC-FDM is basically Orthogonal Frequency Division Multiple Access (OFDM) with pre- and post-coding, frequency bandwidth is efficiently...
Acquiring accurate and coloured 3D representations of underwater scenes is of prime importance in many applications such as ship hull inspection, offshore structure assessment, archaeology or the detection of hazards such as underwater mines. While video and laser-based 3D reconstruction approaches are limited to very short ranges, the use of SONAR sensors enable the recognition and localisation of...
Commercial shipping vessels are a common source of underwater noise in the ocean. This article details a stochastic model for generating frequency-rough emission spectra for different classes of commercial shipping vessels. The model incorporates discrete probability density functions (PDFs) for different ship classes as well as class-dependent conditional PDFs of ship speed and length. Realistic...
An enhanced current meter was deployed in the Antarctic in March, 2017, to measure vertical heat flux in the deep ocean. The purpose of this measurement of flux is to understand how mixing of dense Weddell Sea Bottom Water becomes Antarctic Bottom Water (AABW), the densest water of the Atlantic Ocean outside of trenches. Deep mixing is one of the problems that is not yet well understood despite its...
The method of compressive sensing is applied to moving source data created by simulation to estimate the mode wavenumbers, mode depth functions and mode amplitudes without any environmental acoustic information, such as sound speed profile or bottom properties. The method needs in principle only data covering a short range span and is thus applicable to a range-dependent environment to estimate the...
This work assesses the ability of tidal resources at two locations in the Western Pacific to supply enough power to support persistent oceanographic sensing equipment. We consider the extraction of energy in (1) the three Indonesian straits of Lombok, Ombai, and Timor, and (2) the four Philippines straits of Mindoro, Panay, Tablas, and Dipolog via a small-scale, bottom-mounted turbine. We then relate...
An unmanned vehicle is envisioned for multi-modal operation, first as an aircraft, then as an underwater glider. The benefits of a “Flying Sea Glider” are for high-speed flying ingress above the water and then maneuvering in an area of interest as a low-speed, long-endurance underwater glider. This development builds on previous NRL research in multi-modal designs and bio-inspired propulsion systems,...
With the global energy crisis and environmental pollution intensified, the development of new energy has become the consensus of the world. Among them, ocean, which accounts for 70.8% of the Earth's surface area, contains a wide range and considerable storage of renewable energy. Energy flow density of wave energy is large, which is a low-cost energy source that can provide considerable power through...
The core educational objective of our approach is to use connections between deployed science teams and our target audiences with real-time data to increase awareness and understanding of the Antarctic ecosystem as it responds to global climate change. In 2010–2011 we completed a rigorous field campaign to examine the impact of upwelled Modified Circumpolar Deep Water (MCDW) on the Ross Sea ecosystem...
This paper discusses the construction of search games as a planning method to optimize the effectiveness of UUV search agents. In our previous work, we applied a receiver operator characteristic (or ROC curve) to model the detection performance of search agents operating in adverse environments where false alarms are prevalent. The area search game was developed to maximize the information collected...
Marine pollution caused by oil spills — the release of petroleum hydrocarbons — poses a major threat to marine environments. This has become increasingly true also in the Arctic, where reduced sea ice extent has made Arctic oceans more accessible for industry and tourism-related ship traffic. To minimize the environmental impacts of an oil spill, it is important to identify the source and monitor...
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