This work proposes a localization method using a mechanically scanned imaging sonar (MSIS), which stands out by its low cost and weight. The proposed method implements a Particle Filter, a Bayesian Estimator, and introduces a measurement model based on sonar simulation theory. To the best of author’s knowledge, there is no similar approach in the literature, as sonar simulation current methods target in syntethic data generation, mostly for object recognition . This stands as the major contribution of the thesis as allows the introduction of the computation of intensity values provided by imaging sonars, while maitaining compability with the already used methods, such as range extraction. Simulations shows the efficiency of the method as well its viability to the utilization of imaging sonar in underwater localization. The new approach make possible, under certain constraints, the extraction of 3D information from a sensor considered, in the literature, as 2D and also in situations where there is no reference at the same horizontal plane of the sensor transducer scanning axis. The localization in complex 3D environment is also an advantage provided by the proposed method.

Rio de Janeiro: UFRJ/COPPE, 2017.
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Cochin Port is a major port in the Arabian Sea – Indian Ocean Sea – route and is one of the largest ports in India. The commercial port of Cochin in South-East India is situated in a natural bay connected to Kerala’s backwaters. It has the largest siltation rate among Indian ports: more than 20 million m³ per year. Siltation is pollution of water by fine particulate terrestrial clastic material. Siltation occurs mostly during the Monsoon (June-September) when both river discharges and ocean dynamics are high.

The need for continuous maintenance dredging has serious budgetary impacts for the Cochin Port Trust (COPT). Therefore Cochin Port Trust assigned Antea Group, IIC technologies and Stema Systems to collaborate on a study for the analysis of the siltation processes and to assess the feasibility to implement the nautical depth concept. The latter signifies to investigate the nature of the fluid mud seabed and determine to what extent vessels can sail through and manoeuvre in it.

Wodcon XXI Proceedings 2016.
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The port of Cochin has the largest siltation rate among Indian ports: +20 million m³/year. Local dynamics are controlled by the two rivers discharging into the port system and the ocean. Siltation occurs mostly during the Monsoon (June-September) when dynamics are high (Naik et al., 1983). The Cochin Port Trust (COPT) has tried to optimize the dredging efforts, i.e. allowing ships to partially penetrate the fluid mud. This project is a comprehensive attempt to tackle this problem by understanding the siltation processes in detail and by determining a minimum water depth, draft and under-keel-clearance at which navigation of ships through fluid mud is “safe” (nautical depth). The project was structured in different stages: 1. Desktop study to understand the existing situation and to determine the required acquisition efforts for the development of a numerical 2D model (TELEMAC6 ). 2. Data acquisition and fieldwork to gather the key variables to set up and calibrate the numerical model and undertake the navigation studies. 3. Numerical modeling to understand in detail the siltation processes that occur in the area by simulating the hydrodynamics conditions (waves, tides and currents) as well as sediment transport, erosion and siltation processes. After calibration and validation, the model was used for scenario analysis. 4. Navigation studies to determine a nautical depth. Firstly, the navigation conditions were modeled physically by replicating (1) natural conditions under laboratory environment, (2) selecting a number of maneuvers with chosen design ships with different under keel clearance (UKC) levels and (3) determining mud rheology at the towing tank from the Flanders Hydraulics Research (FHR). Secondly, the results obtained in the physical model were compared against the expert judgement of pilots from the Port of Cochin. For this, tests in the 3D navigation simulator from the FHR, replicating Cochin’s hydrodynamic and environmental conditions, were developed. For this project, the nautical depth criterion was defined with a conservative mindset, by assessing “safe navigation” in terms of maneuverability of vessels. Recommendations to support the implementation of this criterion were provided to the client. The combination of all achieved results allowed the COPT to optimize their maintenance dredging strategy, while keeping sufficient nautical depth. In order to reach greater economic success, the nautical depth criterion needs to be fine-tuned in future works.

CEDA Dredging Days 2017, At Rotterdam
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The North Carolina State University’s Department of Marine, Earth, and Atmospheric Sciences and Center for Marine Science and Technology recently acquired a SeaRobotics MiniCat Unmanned Surface Vehicle (USV). The USV is designed to operate in shallow water, coastal, harbor, riverine, and lake environments. The USV can operate with two different instrument configurations. 1) A seabed-mapping package with an Edgetech 6205 bathymetric and side-scanning sonar with integrated sub-bottom profiler, or 2) a watercolumn mapping package with a Rowe 1200Khz Seaprofiler Acoustic Doppler Current Profiler (ADCP) and multi-component data logger which collects information on water temperature and salinity, as well as the concentration of Chlorophyll-a and dissolved organic matter. The USV has been deployed to Lake Raleigh, Falls Lake, and the North Carolina coast. Initial sea trials and validation have focused on the use of the seafloor-mapping package. Both the side-scan and the bathymetric data collected by the USV have the capability to resolve sub-meter features on the seabed or lake floor. Such high-resolution data will allow the USV to be used for detailed habitat mapping, monitoring of coastal restoration efforts and geo-hazard studies. The water-column mapping package will be used for environmental and water quality studies along coasts and lakes throughout the southeastern United States.

NC State University Undergradute Research Symposium 2016.
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Changes of subaqueous topography in shallow offshore water pose safety risks for embankments, navigation, and ports. This study conducted measurements of subaqueous topography between Datong and Xuliujing in the Yangtze River using a SeaBat 7125 multi-beam echo sounder, and the channel change from 1998 to 2013 was calculated using historical bathymetry data. The study revealed several important results: (1) the overall pattern of changes through the studied stretch of the river was erosion–deposition–erosion. Erosion with a volume 700×10⁶ m³ occurred in the upper reach, deposition of about 204×10⁶ m³ occurred in the middle reach, and erosion of about 602×10⁶ m³ occurred in the lower reach. (2) Dunes are the most common microtopographic feature, accounting for 64.3% of the Datong to Xuliujing reach, followed by erosional topography and flat river topography, accounting for 27.6% and 6.6%, respectively. (3) Human activities have a direct impact on the development of the microtopography. For instance, the mining of sand formed holes on the surface of dunes with lengths of 20–35 m and depths of 3–5 m. We concluded that the overall trend of erosion (net erosion volume of 468×10⁶ m³) occurred in the study area mainly because of the decreased sediment discharge following the closure of the Three Gorges Dam. However, other human activities were also impact factors of topographic change. Use of embankments and channel management reduced channel width, restricted river meandering, and exacerbated the erosion phenomenon.

Science China Earth Science 61(7) · April 2018
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In this software project, the design and implementation of a modular Acoustic Doppler Current Profiler (ADCP) parser is presented. The application was developed as a software project for General Acoustics e.K. a company residing in Kiel, Germany. The reasons that lead to this software project originated in a project in the Iraq. The decision to move the ADCP data parsing location from the onshore server to an offshore platform required the implementation of a platform independent parser. The goal was to create a flexible, efficient, component based, and portable solution to parse ADCP data. The design of the application should also allow later extension with new functionality. It was implemented in modern C++11 using the Boost C++ libraries and a thread-based architecture.

SOFTWARE PROJECT – Communication Systems Group, Prof. Dr. Burkhard Stiller 2016
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The 2016 demonstration cruise of the MIDAS project was conducted to apply existing and novel methods for habitat mapping in a real-world scenario to investigate their applicability to deep sea mining scenarios. With the help of the excellent NIOZ RV Pelagia and their fantastic crew, different image sampling strategies were conducted to better understand their feasibility and practicality. All stations were conducted at Condor seamount off the coast of the island of Faial (Azores, Portugal).


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A pair of self-contained acoustic Doppler current profilers (SC-ADCPs) operating with different frequencies were moored on a muddy sea bottom at about 20 m depth in the Bay of Vilaine off the French Atlantic coast. With their acoustic beams oriented upwards, the SC-ADCPs ensonified most of the water column. The results of several months of in situ recorded echo intensity data spanning 2 years (2003 to 2004) from the dual-frequency ADCPs are presented in this paper. The aim was to estimate suspended particle mass concentration and mean size. A concentration index CI is proposed for the estimation of particle concentration. Based on theory the CI—unlike the volume backscatter strength—does not depend on particle size. Compared with in situ optical data, the CI shows reasonable precision but not increased with respect to that of the highest-frequency backscatter strength. Concerning the mean particle size, despite a lack of quantitative validation with optical particle-size measurements, the method yielded a qualitative discrimination of mineral (small) and organic (large) particles. This supports the potential of dual-frequency ADCPs to quantitatively determine particle size. A cross-calibration of the transducers of each ADCP shows that a specific component of the precision of the backscatter strength measured by ADCP depends on the acoustic frequency, the cell thickness and the ensemble integration time. Based on these results, the use of two ADCPs operating with distinctly different frequencies (two octaves apart) or a single dual-frequency ADCP is recommended.


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This summer research project aimed to achieve several distinct goals. The principal goal was to transform the body of an Unmanned Surface Vessel (USV), specifically a Wave Adaptive Modular Vessel (WAMV), into an autonomous mothership for a Remotely Operated Vehicle (ROV), the VideoRay Pro 4. Another challenge addressed by the research team was finding a way to permanently mount an acoustic Doppler Velocity Log (DVL) to the VideoRay without significantly hindering the VideoRay’s performance. Lastly, the team was tasked with understanding how the DVL recorded data, and how that data could be used to determine location. The Maritime Security Center Summer Research Institute ROV team, located at Stevens Institute of Technology, conducted eight weeks of research to find solutions to these unique challenges.

Maritime Security Center, A Department of Homeland Security Science and Technology Center of Excellence, 2017.
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