Sonar

Title of dissertation: CONCURRENT LOCALIZATION AND MAPPING WITH SONAR SENSORS AND CONSIDERATION OF VEHICLE MOTIONS Hesham Ismail, 2016 Dissertation directed by: Professor Balakumar Balachandran Department of Mechanical Engineering Simultaneous Localization and Mapping (SLAM) is a procedure used to determine the location of a mobile vehicle in an unknown environment, while constructing a map of the unknown environment at the same time. Mobile platforms, which make use of SLAM algorithms, have industrial applications in autonomous maintenance, such as the inspection of flaws and defects in oil pipelines and storage tanks. A typical SLAM consists of four main components, namely, experimental setup (data gathering), vehicle pose estimation, feature extraction, and filtering. Feature extraction is the process of realizing significant features from the unknown environment such as corners, edges, walls, and interior features. In this work, an original feature extraction algorithm specific ...

A dichotomy between depth penetration and resolution as a function of sonar frequency, draw resolution, and beam spread challenges fish target classification from sonar. Moving high-frequency sources to depth using autonomous underwater vehicles (AUVs) mitigates this and also co-locates transducers with other AUV-mounted short-range sensors to allow a holistic approach to ecological surveys. This widely available tool with a pedigree for bottom mapping is not commonly applied to fish reconnaissance and requires the development of an interpretation of pelagic reflective features, revisitation of count methods, image-processing rather than wave-form recognition for automation, and an understanding of bias. In a series of AUV mission test cases, side-scan sonar (600 and 900 kHz) returns often resolved individual school members, spacing, size, behavior, and (infrequently) species from anatomical features and could be intuitively classified by ecologists — but also produced artifacts. Fi...

Depth profiling via remotely-controlled boats using sonar in Wastewater Treatment Ponds, WWTPs, has been proposed as an alternative to the traditional practice of surveying with manned boats. Sediment hardness derived from the sonar profiling yields an index value corresponding to sediment densities across the surveyed pond. Mapped sediment hardness will define sludge distribution and typing within WWTPs. Sludge typing supports further understanding of the transfer, deposition, and settling of sludge in treatment ponds. Sediment hardness can also correlate to observations of very low density suspended/flocculated sludge existing at the sludge/water interface as found when using sludge samplers.

This is MATLAB's 10 most easy & most basic programs that I's supposed to submit in my practicals. In this document I've complied 10 MATLAB programs from basic to advanced through intermediate levels, But overall they are for beginners only. It's only a 26 pages doc. for academic purposes. well, What else a student can offer you, huh? LOLz

A warship at sea functions like a huge sea creature in respect of a majority of its functions. For example, there is a need for a ship to see, listen, and communicate; it uses Radars, Sonars and Communication equipment for these tasks. The overall goal of the warship is to identify and eliminate the threats arising at sea, thus all the equipment on board a warship is required to function in unison to achieve this aim. Emphasis in this article would be on Communication equipment, discussion on technological aspects of Radars and Sonars would be limited to essentials

The risks military sonar poses to cetaceans received international attention with
a highly-publicized mass stranding of Cuvier’s beaked whales (Ziphius cavirostris),
Blainville’s beaked whales (Mesoplodon densirostris), and northern minke whales
(Balaenoptera acutorostrata) in the Bahamas in 2000. This was the first time that the
US Government determined a stranding to be the result of mid-frequency active sonar
use. Subsequently attention has been drawn to other mass strandings coincident with
naval exercises, including events preceding the 2000 mass stranding. The list of species
for which mass strandings have been linked to naval exercises has also increased to
include other beaked whales, dwarf and pygmy sperm whales (Kogia spp.), pilot whales
(Globicephala spp.), several dolphin species (Stenella sp. and Delphinus delphis), and
harbor porpoises (Phocoena phocoena). In particular, there have been several mass
strandings in the northern Indian Ocean coincident with naval exercises—including one
of the largest (200–250 dolphins)—which have received little attention. Changes in
beaked whale behavior, including evasive maneuvering, have been recorded at received
levels below <100 dB re 1μPa (rms) and mass stranding may occur at received levels
potentially as low as 150–170 dB re 1μPa. There is strong scientific evidence to suggest
that a wide range of whale, dolphin and porpoise species can also be impacted by sound
produced during military activities, with significant effects occurring at received levels
lower than previously predicted. Although there are many stranding events that have
occurred coincident with the presence of naval vessels or exercises, it is important to
emphasize that even the absence of strandings in a region does not equate to an absence
of deaths, i.e., absence of evidence does not mean evidence of absence. Strandings
may be undetected, or be unlikely to be observed because of a lack of search effort
or due to coastal topography or characteristics. There may also be “hidden” impacts of
sonar and exercises not readily observable (e.g., stress responses). Due to the level of
uncertainty related to this issue, ongoing baseline monitoring for cetaceans in exercise
areas is important and managers should take a precautionary approach to mitigating
impacts and protecting species.

"Монография посвящена описанию теории пространственно-временной обработки гидроакустических сигналов с учетом сложного перемещения антенны в пространстве, помех и особенностей среды распространения колебаний, а также теории быстрой многоканальной обработки гидроакустических сигналов.
Для специалистов, занимающихся разработкой методов и алгоритмов пространственно-временной обработки сигналов, программистов, реализующих алгоритмы многоканальной обработки сигналов, а также разработчиков гидроакустических и радиолокационных систем.
"

In this paper, a simulation framework that can be utilized during the simulation and algorithm selection phases of active sonar system development for surface and subsurface platforms, are described. HAVELSAN will have the capability to develop techniques and perform the performance analysis of
different methods that can be used in different areas like target detection sonars, torpedo sonars and mine hunting sonars with this simulation framework.

The exploration of oceans and sea beds is being made increasingly possible through the development of Autonomous Underwater Vehicles (AUVs). This is an activity that concerns the marine community and it must confront the existence of notable challenges. However, an automatic detecting and tracking system is the first and foremost element for an AUV or an aqueous surveillance network. In this paper a method of Kalman filter was presented to solve the problems of objects track in sonar images. Region of object was extracted by threshold segment and morphology process, and the features of invariant moment and area were analysed. Results show that the method presented has the advantages of good robustness, high accuracy and real-time characteristic, and it is efficient in underwater target track based on sonar images and also suited for the purpose of Obstacle avoidance for the AUV to operate in the constrained underwater environment.

We wrześniu 2019 roku zakończył się grant Narodowego Centrum Nauki, realizowany przez Wydział Humanistyczny US, a poświęcony interdyscyplinarnym badaniom wraków odrzańskich. Wykazały one, że Dolna Odra jest akwenem nadzwyczaj zasobnym w zatopione pamiątki przeszłości.

In the Cedynia-Gozdowice-Siekierki Region of National Remembrance (Gryfino county, Poland) a wreck of a military boat was discovered in 2015. The boat was identified as an element of light pontoon bridge park NLP, used by Red Army and Polish People’s Army during World War II. The boat sank in Odra (Oder) river, probably during the fights with Nazi German troops in 1945.

Sonars (Sound Navigation and Ranging) are used extensively for underwater sensing on Autonomous Underwater Vehicles (AUV). The images received from the sonar tend to be noisy. So, it is very difficult to extract the information about the target. Hence before going to the display system post-processing is required. This paper describes an attempt to reduce the noisy problems of sonar images. The results are compared visually as well as in terms of SNR.

The quality of the transmission signal should be very good for active sonar applications like detection, tracking, communication, fish location, acoustic oceanography etc. One of the best ways to achieve it is by using a PWM signal. This paper presents various schemes for generating PWM signals for active sonar applications. There are two types of PWM signals and they can be generated using microcontroller, hardware and software schemes. The analysis of types and generation of PWM is also described. The analysis is done using Xilinx and Matlab.

This paper presents a comprehensive overview of current deep-learning methods for automatic object classification of underwater sonar data for shoreline surveillance, concentrating mostly on the classification of vessels from passive sonar data and the identification of objects of interest from active sonar (such as minelike objects, human figures or debris of wrecked ships). Not only is the contribution of this work to provide a systematic description of the state of the art of this field, but also to identify five main ingredients in its current development: the application of deep-learning methods using convolutional layers alone; deep-learning methods that apply biologically inspired feature-extraction filters as a preprocessing step; classification of data from frequency and time–frequency analysis; methods using machine learning to extract features from original signals; and transfer learning methods. This paper also describes some of the most important datasets cited in the l...

In this paper, the requirements and components of an acoustic signal processor used in surface and underwater systems are defined. The considered details and constraints during the development of an real time acoustic processor as an R&D project of HAVELSAN will be explained.

Raport końcowy z poszukiwań przeprowadzonych w listopadzie i grudniu 2020 roku, napisany na użytek Wojewódzkiego Urzędu Ochrony Zabytków w Zielonej Górze – Delegatury w Gorzowie Wielkopolskim, placówek Państwowego Gospodarstwa Wodnego Wody Polskie (Regionalnych Zarządów Gospodarki Wodnej w Szczecinie, Poznaniu i Wrocławiu oraz Zarządów Zlewni w Gorzowie Wielkopolskim i Zielonej Górze), a także Urzędu Żeglugi Śródlądowej w Szczecinie. 27 stron, 5 fotografii, 7 sonogramów, mapa, tabela i załącznik.

Wrak Szczecin Zdroje 1 (SZD1), spoczywający w Regalicy, od lat budził zainteresowanie badaczy podwodnego dziedzictwa archeologicznego. Podjęte w latach 2010-2019 prospekcje przy użyciu sonarów (stacjonarnego i bocznego) oraz echosondy interferometrycznej nie pozwalały bowiem zidentyfikować typu zatopionego statku, ani dokładnie rozpoznać jego detali widocznych na zobrazowaniach. Autorzy we wrześniu 2019 roku ponownie przebadali wrak, wykorzystując jednak inne urządzenie hydrolokacyjne – podwodną kamerę akustyczną ARIS, umożliwiającą rejestrację przestrzeni podwodnej w sposób analogiczny do kamery optycznej, ale nie wymagającą naturalnego ani sztucznego oświetlenia. Badania wykonano z pokładu statku szkoleniowo-badawczego „Echo 2”, którego armatorem jest spółka ESCORT. Na podstawie ich wyników nie tylko zidentyfikowano typ zatopionego statku, dokładnie rozpoznano jego detale konstrukcyjne i ogólny stan zachowania, lecz także sformułowano hipotezę dotyczącą przyczyn zatonięcia jednostki.

Abstract, This paper examines the potential for remote classifica-tion of seafloor terrains using a combination of quantitative acoustic backscatter measurements and high resolution bathyme&apos; try derived from two classes of sonar systems currently used by the marine research community: multibeam echo-sounders and bathymetric sidescans sonar systems. The high-resolution bathymetry is important, not only to determine the topography of the area surveyed, but to provide accurate bottom slope correc-tions needed to convert the arrival angles of the seafloor echoes received by the sonars into true angles of incidence. An angular dependence of seafloor acoustic backscatter can then be derived for each region surveyed, making it possible to construct maps of acoustic backscattering strength in geographic coordinates over the areas of interest Such maps, when combined with the high-resolution bathymetric maps normally compiled from the data output by the above sonar systems, could be ver...

SZD1 shipwreck is the largest of 11 wrecks resting in the Regalica River (West Pomerania, Poland) registered during the project "Underwater Ethnoarchaeology of the Lower Oder. Preliminary Research on Wrecks in Selected Sections of the River" (grant no. 2018/02/X/HS3/00475, National Science Centre, Poland). It has been an object of interest for explorers and scholars over the years, because previous investigations by the means of sonars (stationary and side-scan) and interferometric echosounder had not allowed identifying its type accurately and recognizing details visible on the recorded images. Authors of the poster have reached a conclusion that it has been necessary to investigate the wreck one more time by the means of another kind of sonar – ARIS acoustic camera, that allows to record underwater space in analogous way to optical video camera. Investigation has been carried in October 2019 on board of research vessel “Echo 2” owned by ESCORT Sp. z o.o. During the investigation, high quality video records have been made, allowing not only identifying the type of sunken vessel, but also recognizing her construction details. Moreover, ship’s hull damages were observed, so that it has become possible to enunciate the hypothesis about the reason of her sinking.

The project ‘Underwater Ethnoarchaeology of the Lower Oder. Preliminary Research of Shipwrecks in the Selected Sections of the River’ is funded by the National Science Centre, Poland (grant no. 2018/02/X/HS3/00475) and carried by the University of Szczecin (West Pomerania, Poland) in the time period of 2018–2019. It assumes application of information gathered during ethnological fieldwork for the use of underwater archaeology.
During structured interviews with representatives of social groups related by occupation or hobby to the Lower Oder (e.g. seamen, fishermen, divers, anglers, sailors etc.) the data concerning any known wrecks is being gathered – along with the broad context: spatial (localization, position, orientation) and socio-cultural (toponymy, beliefs, convictions of types and provenience of sunken watercrafts). On this basis sections of the river were selected, with the highest number of located wreck sites. These areas were prospected with the use of side-scan sonar and an unmanned aerial vehicle (UAV). The next stage of research (for now yet unaccomplished) is the elaboration of bathymetric maps. The spatial analysis of the data gathered this way will be used to designate areas for underwater archaeological research. It will consist of making the photographic and video documentation during diving reconnaissance, and then descriptive and graphic documentation of selected wreck sites.
The results of the ethnological fieldwork allowed determining not only the areas where wrecks are located, but also their socio-cultural context – how they are functioning in the consciousness of people residing by the Lower Oder. On the other hand, the results of archaeological fieldwork will enable to verify the accuracy of convictions and beliefs regarding shipwrecks, and also determine the scope and methods of further research upon discovered underwater archaeological sites.

The paper presents connections between the criteria which make three types of objects possible to be recognized, namely, edges, planes and corners. These criteria can be applied while a binaural sonar system is used. It is shown that the criteria are specific forms of a general equation. The form of the equation depends on a single coefficient. In the paper, the meaning of this coefficient is discussed. The constructions of the arrangement of objects are presented and are bound with values of the coefficient.

In the paper, an idea of a method of signal arrival direction estimation is presented. The influence of time error measurements on the usage of the method is described. An approach to the problem of an increase in the robustness of the method is proposed. The results of experiments are presented and discussed.

—This paper suggests using a wideband sonar system to detect and classify human activity in indoor environment. While most existing sonar systems used for assessment of human activity are based on a narrowband Doppler based technology, this paper suggest using wideband sonar. It enables precise tracking of body parts, and its enhanced correlation properties can be used to distinguish between human and non-human objects. Maximal Likelihood (ML) criterions to derive kinematic features and analytical methods to estimate the subject activity level and activity type were derived and tailored to the wideband sonar. For tracking and association of the echoes reflected from the different body part, we developed an efficient approximation of the sequential ML estimator. The algorithm works in the natural time-space domain, which eases the exploitation of the a-priori knowledge about the human subject target. For classification of the activity, a weighted two level nested k-Nearest Neighbor classifier was applied on only four kinematic features. A set of experiments with five subjects, performing three different activity types of standing, walking, and swinging upper limbs, was carried out in a typical indoor environment. The proposed technology has managed to classify well the different activity types and demonstrated the potential of this technology for continuous assessment of various kinematic features of humans in indoor environment with reduced costs, under any light, smoke, or humidity conditions. This can be useful for instance for monitoring patients at home, and for detecting intruders.

National security problem raises with major threats i.e. illegal activities at border areas and few others are examples of those. Even if government provides bullet proof jackets and high quality guns to our armed forces, yet it is hard to resolve such issues. In such operations when forces are not able to push their strength beyond human efforts, we can implement Artificial Intelligence based machines to put into action. In this paper, it is described that a machine will identify the region of my country, other country and display on LCD. And it takes appropriate action according to valid region. Also, this system check the id for valid person and take an appropriate action for invalid persons such as operate the laser shooter that identifies the suspected person and display all conditions in LCD at border. This system checks the force member id wirelessly.

A generalization of the Wiener filter to minimize signal distortion in the additive noise reduction problem is proposed. Two performance criteria are discussed, to take distortion
and signal-to-noise ratio improvements into account. Results of applying the generalized filter to a random signal with exponential correlation function and to real underwater acoustic signal are presented.

"Methane is common in organic-rich marine and freshwater sediments. Escape of this gas via ebullition is the most efficient
mechanism of methane transport from the shallow sediments to the atmosphere. Therefore characterization and quantification of free gases in surface sediments is an important ecological issue. High spatial heterogeneity of methane distribution does not allow using conventional sampling methods for representative quantification of sedimentary gases over large areas, such that development of remote-sensing methodology is required to investigate gassy sediment distribution. In this paper we compare the results of acoustical sampling to study sound scattering in soft gassy sediments in two deep subtropical lakes - Lake Kinneret and Lake Biwa. Acoustic samplings were carried out using 70 kHz and 120 kHz single beam echosounders along standard transects. To determine the typical acoustic features of gassy sediments we conducted echo envelope parameterisation using different spectral, wavelet, fractal, statistical and energy parameters. A number of parameters appeared to be sensitive to the presence free gases in sediments. Comparison of the results obtained on two lakes allows detecting the effect of sediment type, its location, and water level change on acoustic properties of the top layer of gassy sediments."