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Ocean Environmental data is a key component utilized by the United States Coast Guard (USCG) when developing and executing a search and rescue mission. The Search and Rescue Optimal Planning System (SAROPS) became operational with the USCG in 2007 and is the main tool for developing search and rescue mission plans. This tool utilizes environmental data (wind, ocean currents, etc.) to estimate the...
The purpose of this research is to develop a solar-powered autonomous surface vehicle (SASV) for the use of ocean environment monitoring and underwater passive acoustic monitoring of marine mammals. Measuring items of the logger version CTD with optical fast DO sensor are depth, temperature, conductivity, salinity, dissolved oxygen, chlorophyll and turbidity. The authors have also developed kinds...
An underwater wireless sensor network (UWSN) has multiple functions in ocean survey. A kind of UWSN has been proposed by Zhejiang University. In this paper the CFD method is utilized to verify the ability of a node to adjust its posture in deploying and recovering process. The minimum depth and the minimum time for a node to adjust itself to vertical were obtained in different initial inclined angles...
The distance of conventional X-band microwave propagation over the sea surface is within ‘radio line-of-sight’ (RLOS) which limits its application in long-range land-buoy communication. To overcome the above limitation, evaporation duct (EVD) is employed as an alternative to the physical channel in the land-buoy communication and the corresponding communication distance could be extended to hundreds...
Flooding disasters have led to heavy costs including enormous property losses and casualties. The biggest challenge lies in rescue operation is the low efficiency and the high security risk of rescuers, which is also a problem focused on by this work. Unmanned system is one of the solution that replace people in the rescue operation. However, there are still some obvious defects of unmanned system...
This paper will describe a compact energy generation and storage system to harvest temperature differentials in the ocean. This is a unique power source underwater in the absence of solar and wave energy. The current state-of-the-art autonomous underwater vehicles and sensors are mostly powered by primary battery, and therefore have limited capacity and lifetime. Harvesting the ocean thermal energy...
In this paper, an approach is presented to retrieve ionospheric total electron content (TEC) over oceans from Global Navigation Satellite System-Reflectometry (GNSS-R) delay-Doppler map (DDM). Here, an additional ionospheric delay (τI) is considered in the conventional DDM simulation process. Based on this, the least squares (LS) fitting method is employed for TEC retrieval by fitting the simulated...
Gliders are the state-of-the-art autonomous underwater vehicles (AUV) that can operate unattended for roughly a month-long period in the ocean. Given a forward horizontal speed of 0.25 ms−1, gliders can cover ∼ 25 km per day. They trace sawtooth profiles in the ocean by changing buoyancy, observing subsurface temperature, conductivity, and other water properties versus depth, and at the surface, fix...
A fast, recently developed, Least Square regression method based on Discrete Cosine Transform (DCT-PLS) algorithm has been adapted to the mapping of hourly High Frequency Radar (HFR) data in the seas surrounding Taiwan. HFR is a shore based remote sensing system, and can be subject to unexpected observation failure. This algorithm produces both solution and error estimates of oceanographic data. The...
This paper proposes a solution for recovery of spilled oil on dangerous water area with an Unmanned Surface Vehicle(USV). A Dynamic Inclined Plane Skimmer(DIPS) is placed on the front deck of the USV so that it can run to the destination at high speed. For automatic deployment of the DIPS onto the water, a mechanism consisting of two pillars fixed on each side of the front deck, a portal-type frame...
Malaysian Airlines Flight 370 disappeared on 8 March 2014, while flying from Kuala Lumpur, Malaysia, to Beijing, China. A piece of marine debris, later confirmed to be a flaperon from Flight 370 by the French prosecutor, was found on Réunion Island in the western Indian Ocean on 29 July, 2015. The aircraft debris are assumed to drift in the surface layer and the vertical movement is not taken into...
Multifunctional hybrid glider(MHG) is a new type of platform for ocean observation, integrating the concept of underwater glider and wave glider. The implementation scheme of its motion mechanism is proposed in this paper, and with the rubber webbed wings introduced and the structure redesigned, this vehicle can glide on the ocean surface and in the vertical profile. This can overcome the shortcomings...
This paper presents a single-hydrophone based method for source range localization from information contained in the multipath propagation in the reliable acoustic path (RAP) environment. The time delays between the direct (D) and the surface-reflected (SR) arrivals are obtained from the autocorrelation of the received signal and are compared with the D-SR time delays predicted by the acoustic model...
Capping contaminated sediments is an in situ remediation technique by placing capping material on top of the sediments to prevent continued contamination of surface water and biota from contaminated sediments. Capping is considered as much cheaper than dredging and is expected to be very effective to block the diffusion of contaminants in short-term. The research on capping material for controlling...
A new small-sized autonomous surface vehicle actuated by a water-jet has been developed at INESC TEC for search and rescue of victims at sea. This paper describes the vehicle main components and presents the control and guidance laws governing the motion and enabling it to perform line-following and target tracking missions. Results from field trials are presented, demonstrating the capabilities and...
A new multi-frequency HF (MHF) radar based on small circular antenna array is briefly introduced in this paper. For the purpose of reducing the area of receiving array, Radio Ocean Remote Sensing Laboratory of Wuhan University designed a small receiving array, which consists of 7 elements with a diameter of 5 meters, for MHF radar system in 2014. This new MHF radar system, adopting Frequency Modulated...
We examined characteristics of material transport and a tidal front formation in a semi-enclosed bay, Korea, based on numerical experiment results. Pollutant diffusion resulted in a relatively high concentration in the northwest part of the bay compared to the other area, because of inactive flow and topographic factor. The diffusion area of pollutant appeared 3.25km2 in the spring, 4.62km2 in the...
Prediction of vibration and radiation from large underwater structures is one of the most important research contents in engineering. The cylindrical shell structure is most common structure in engineering, and it is the main component of submarine at the same time. Shells with structural similarity have similar properties due to the similarity principle. Free vibration of the simple cylindrical shell...
Matched field processing (MFP) for passive source localization is a comprehensive application of signal processing techniques in extremely complex environment. In essence, it is a parameter estimation processor by exploiting full wave modeling of acoustic waveguide propagation. Typical MFP performance demonstrates a threshold behavior, that is, below some signal-to-noise ratio (SNR), the mean-square...
In shallow water, loud surface ships can mask the weak signal of the underwater target. In this case, the localization of the target is difficult due to side-lobes of the interferers. By incorporating the prior knowledge of the uncertain parameters, we have proposed a robust localization method [Liu, et al. Robust source localization using predictable mode subspace in uncertain shallow ocean environment...
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