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Search results for: sonar boczny
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Sonar Pulse Detection Using Chirp Rate Estimation and CFAR Algorithms
PublicationThis paper presents a new approach to sonar pulse detection. The method uses chirp rate estimators and algorithms for the adaptive threshold, commonly used in radiolocation. The proposed approach allows detection of pulses of unknown parameters, which may be used in passive hydrolocation or jamming detection in underwater communication. Such an analysis is possible thanks to a new kind of imaging, which presents signal energy in...
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Multibeam Sonar Characterisation of Seafloor in the Context of Visualisation and Dissemination of Marine Data
PublicationThe paper presents the seafloor characterisation method based on multibeam sonar data. it relies on using three types of multibeam seafloor sensing data: 1) the grey-level sonar images (echograms) of seabed, 2) the 3D model of the seabed surface which consists of high resolution bathymetric data, 3) the set of time domain bottom echo envelopes received in the consecutive sonar beams. The classification is performed by utilisation...
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Broadband LFM signal source for a module-based diver detection sonar
PublicationPraca przedstawia koncepcję źródła impulsów sondujących sonaru DDS, dla pogrupowanych po stronie nadawczej elementarnych sekcji przetwornika w moduły 8 lub 16 elementowe. Na podstawie oszacowania teoretycznego i pomiarów czwórnikowych określono potrzebną moc wyjściową i topologię tych nadajników. Przedstawione są też uzyskane na drodze pomiarów charakterystyki częstotliwościowe modułów przetwornika, razem z zastosowanym układem...
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Distance measurement errors in silent FM-CW sonar with matched filtering
PublicationThe secretiveness of sonar operation can be achieved by using continuous frequency-modulated sounding signalswith reduced power and significantly prolonged repeat time. The application of matched filtration in the sonarreceiver provides optimal conditions for detection against the background of white noise and reverberation, and avery good resolution of distance measurements of motionless targets. The article shows that target...
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Time variable gain for long range sonar with chirp sounding signal
PublicationThe main purpose of applaying Time Variable Gain (TVG) in active sonars with digital signal processing is to reduce dynamic range of echo signal and adapt it to the dynamic range of the analogue to digital conversion. With high transmission losses level, the dynamic range of the input signal in long range sonars can be very high and even exceed 200dB. When chirp sounding signals with matched filtration are used, sonars can raech...
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Methodology for Processing of 3D Multibeam Sonar Big Data for Comparative Navigation
PublicationAutonomous navigation is an important task for unmanned vehicles operating both on the surface and underwater. A sophisticated solution for autonomous non-global navigational satellite system navigation is comparative (terrain reference) navigation. We present a method for fast processing of 3D multibeam sonar data to make depth area comparable with depth areas from bathymetric electronic navigational charts as source maps during...
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Roczny raport 2006
PublicationPrezentacja rocznego raportu gdańskiej firmy wodociągowej: SAUR Neptun Gdańsk (SNG).
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Alternative Energy: Photovoltaic Solar Cells
Publication...
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Alternative Energy: Photovoltaic Solar Cells
PublicationSolar radiation is a fuel for photovoltaic cells and modules, which are a source of electric energy. Viable solar technologies that have been developed in the past are starting to be adopted on a broader and more meaningful global scale across different sectors with ever-increasing market penetration. In this entry, a brief overview of the material properties relevant to solar cell operation, the structure of the solar cell, and electrical...
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Solar Photovoltaic Energy Optimization and Challenges
PublicationThe study paper focuses on solar energy optimization approaches, as well as the obstacles and concerns that come with them. This study discusses the most current advancements in solar power generation devices in order to provide a reference for decision-makers in the field of solar plant construction throughout the world. These technologies are divided into three groups: photovoltaic, thermal, and hybrid (thermal/photovoltaic)....
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Hydrogen generation using solar energy
PublicationWodór jest uważany za alternatywne i odnawialne źródło energii. Bezpośrednie wykorzystanie światła słonecznego do fotokatalitycznego lub fotoelektrochemicznego rozkładu wody może zapewnić w przyszłości ekonomicznie uzasadnione, alternatywne źródło wodoru. W wystąpieniu przedstawione zostały wyniki dotychczasowych prac związanych z hybrydową, fotowoltaiczno-elektrochemiczną instalacją do rozkładu wody oraz omówione zostały kierunki...
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Hydrogen generation using solar energy
PublicationWodór jest uważany za alternatywne i odnawialne źródło energii. Bezpośrednie wykorzystanie światła słonecznego do fotokatalitycznego lub fotoelektrochemicznego rozkładu wody może zapewnić w przyszłości ekonomicznie uzasadnione, alternatywne źródło wodoru. W pierwszym etapie naszych badań został zaprojektowany i zbudowany hybrydowy, fotowoltaiczno-elektrochemiczny układ, dokonujący konwersji energii promieniowania słonecznego na...
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Solar Photovoltaic Energy Optimization and Challenges
PublicationThe study paper focuses on solar energy optimization approaches, as well as the obstacles and concerns that come with them. This study discusses the most current advancements in solar power generation devices in order to provide a reference for decision-makers in the field of solar plant construction throughout the world. These technologies are divided into three groups: photovoltaic, thermal, and hybrid (thermal/photovoltaic)....
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ENVIRONMENTAL ASSESSMENT OF SOLAR CELL MATERIALS
PublicationIn today’s world, fossil fuels, including coal, oil, and gas, are the primary energy sources from which electricity is obtained. As they are exhaustible and their exploitation has a negative impact on the natural environment, they should be, at least partially, replaced by renewable energy sources. One of these sources is solar energy. The use of solar energy releases no CO2, SO2, or NO2 gases, and does not contribute to global...
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Kalman filtering for 3d real time data visualisation of multibeam sonar records.
PublicationPrzedstawiono zastosowanie filtracji Kalmana do korekcji błędów systematycznych występujących w danych pochodzących z systemu wielozwiązkowego. Zaproponowano dwuetapową filtrację danych dla każdego wachlarza danych, która realizowana jest w czasie rzeczywistym. Zaprezentowano rezultaty wizualizacji dna morskiego przed i po filtracji.
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Safety enhancement using 3D multibeam sonar imaging in shallow waters areas
PublicationSonary wielowiazkowe wykorzystanee byc moga do poprawy bezpieczenstwa zeglugi na obszarach wod plytkich. Dzieki istotnej poprawie rozdzielczosci horyzontalnej i wertykalnej pomiarow zastosowane byc moga do obrazowania wod plytkich szczegolnie niebezpiecznych pod wzgledem nawigacyjnym.
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Dynamic control of the receiving beam horizontal cross-section in the side scan sonar
PublicationW skonstruowanych przed kilkunastu laty a obecnie modernizowanych sonarach bocznych jako jeden z zabiegów modernizacyjnych wprowadzono dynamiczną regulację kąta rozwarcia odbiorczej charakterystyki kierunkowej w przekroju horyzontalnym. Regulacja taka zapewnia quasi-stałą rozdzielczość liniową sonaru (zamiast stałej rozdzielczości kątowej) przy odbiorze sygnałów echa ze wzrastających odległości od wykrywanych celów. W efekcie tego...
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Improving the accuracy of bearing in active sonar with cylindrical array using spectrum estimation.
PublicationThe articles presents a method for improving the accuracy of bearing in multibeam sonar with a cylindrical array. Based on a known spatial spectrum estimation technique, the method has been successfully used in linear array systems. Its accuracy of bearing is satisfactory and ensures a relatively low computational effort. The article discusses certain simplifications and assumptions to adapt the spatial spectrum estimation technique...
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THE SYNCHROSQUEEZING METHOD IN BEARING ESTIMATION OF STATIONARY SIGNALS FOR PASSIVE SONAR WITH TOWED ARRAY
PublicationIn this paper, a novel method of bearing estimation in a passive sonar system with a towed array is introduced. The classical approach of bearing estimation based on the spatial spectrum [1] is extended by using the synchrosqeezing method that is a part of the reassignment method introduced by Kodera et al. [2]. Using this method leads to a precise bearing estimation. The proposed method requires a relatively small amount of computation,...
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Continuous wave sonar with hyperbolic frequency modulation keyed by pseudo-random sequence
PublicationA CW FM type sounding signal is used in the classical solution of silent sonar. While the signal provides a relatively simple implementation of digital signal processing, and ensures good detection conditions, unfortunately, in the presence of the Doppler effect, distance measurement results tend to be wrong. This is due to the fact that the received signal’s instantaneous frequency value is dependent both on the distance to the...
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Analysis of distance measurement errors in CW FM sonar with MLS code modulation
PublicationAlthough used in the classic silent sonar, the CW FM sounding signal has a major flaw which is its inaccuracy in determining the distance to a target. The authors of the article have developed a concept of silent sonar using frequency modulation signals switched by pseudorandom codes, already discussed in their previous work. This article presents a detailed analysis of errors in CW FM sonar with pseudo-random sequence code modulation...
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Combined method of multibeam sonar signal processing and image analysis for seafloor classification
PublicationThe combined approach to seafloor characterisation was investigated. It relies on calculation of several descriptors (parameters) related to seabed type using three types of multibeam sonar data obtained during seafloor sensing: 1) the grey-level sonar images (echograms) of seabed, 2) the 3D model of the seabed surface which consists of bathymetric data, 3) the set of time domain bottom echo envelopes received in the consecutive...
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Seafloor characterisation using multibeam sonar echo signal processing and image analysis
PublicationThe authors propose the approach to multibeam seafloor characterisation which relies on the combined, concurrent use of two different techniques of multibeam sonar data processing. The first one is based on constructing the grey-level sonar images of seabed using the echoes received in the consecutive beams. Then, the parameters describing the local region of sonar image, namely, the local standard deviation of a grey level, and...
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Multistatic sonar for man-made lakes and water-power plants antiterrroristic protection
PublicationArtykuł opisuje nową koncepcję dopplerowskiego sonaru multistatycznego opracowanego w Katedrze Systemów Elektroniki Morskiej Politechniki Gdańskiej. System składa się z sieci hydrofonów rozmieszczonych równomiernie w obserwowanym akwenie oraz ze źródła dźwięku w postaci fali ciągłej o stałej częstotliwości i bardzo niskim natężeniu. Dzięki zastosowaniu specjalnie opracowanych algorytmów przetwarzania sygnałów uzyskuje się poprawną...
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Possibilities of detection and identification objects located on the sea bottom by means of a simple sidescan sonar
PublicationPraca zawiera omówienie zagadnień związanych z wykrywaniem i identyfikacją obiektów leżących na dnie przy pomocy sonaru bocznego, umieszczonego na zdalnie sterowanym pojeździe głębinowym.
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Influence of Natural Conditions on the Imaging of the Bottom of the Gdańsk Bay by Means of the Side Scan Sonar
PublicationThe interest in underwater resources is the reason for the development of modern hydroacoustic systems, including side sonars, which find numerous applications such as: research of seabed morphology and sediment characteristics, preparation of sea sediment maps, and even in special cases of biocenoses such as sea grass meadows, detection of specific targets at the bottom such as shipwrecks, mines, identification of suitable sites...
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3D seafloor reconstruction using data from side scan and synthetic aperture sonar
PublicationSide scan and synthetic aperture sonars are widely used imaging systems in the underwater environment. They are relatively cheap and easy to deploy, in comparison with more powerful sensors, like multibeam echosounders. Although side scan and synthetic aperture sonars does not provide seafloor bathymetry directly, their records are finally related to seafloor images. Moreover, the analysis of such images performed by human eye...
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Experimental evaluation of high frequency side scan sonar as object search and identification tool
PublicationPraca prezentuje wyniki badań laboratoryjnych sonaru bocznego jako narzędzia dla pojazdu podwodnego, służącego do poszukiwań i identyfikacji obiektów leżących na dnie, w bliskich odległościach.
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Combined spline wavelet decomposition for 3d seafloor imaging from multibeam sonar echoes
PublicationThe paper proposes combined spline-wavelet approach to the raw echoes seaflor imaging from Multibeam Sonar System (MBSS) records. Wavelet representation is closely related to image representation, due to its unique approximations properties. Splines have the best approximation properties among all known wavelets of a given order, so they are best suited for approximating of smooth seafloor surface. Additionaly, wavelet bases have...
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Effect of illumination on noise of silicon solar cells
PublicationTransport and noise properties of silicon solar cells in darkness and under illumination have been studied. The measurements were carried out for both reverse and forward bias of the device. The changes in the sample behaviour are due to the variation of PN junction dynamic resistance and, also, the occurence of both 1/f and generation-recombination noise components
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End-Of-Life Management of Photovoltaic Solar Modules
PublicationThe PV industry continues to push its credentials as a technology that addresses one of the fundamental challenges of our times – climate change. There are however two major concerns about this technology: first, the potential negative environmental impacts of energy used in the production stage and second, the possible shortage of the valuable materials in the future. The currently dominant semiconductor used in photovoltaic modules...
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Implementation of Contemporary Technologies in Naval Sonars Modernization
PublicationToday’s fast technological advancement in electronics and signal processing methods makes electronic systems, including sonars, obsolete very quickly. The Polish Navy seems to be particularly affected as its ships were built in the 1970s and 1980s. Researchers at the Gdansk University of Technology have developed a methodology for modernising Navy sonars which involves the use of new electronic sub-systems and modern, bespoke methods...
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Mutual Clutter Suppression Techniques for FM Sonars
PublicationThe article presents methods that help in the elimination of mutual clutter as well as the consequences of two FM sounding signal sonars operating in the same body of water and frequency band. An in-depth analysis of mutual clutter was carried out. The effects of sounding signal differentiation were determined, as was the Doppler effect on mutual clutter suppression. One of the methods analysed is of particular interest in a situation...
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Solar-wind system for lightning of public areas
PublicationSolar-wind system was developed for illumination of public large areas. The energy of this system becomes from renewable sources. Furthermore, they are relatively inexpensive, and the production of pollutants or greenhouse gases are reduced.
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PVT - hybrid photovoltaic - thermal solar systems
PublicationPVT - to urządzenia, łączące ze sobą funkcje modułu fotowoltaicznego i kolektora słonecznego, w którym rolę absorbera pełni moduł ogniw fotowoltaicznych. Umożliwia to otrzymywanie z tej samej powierzchni pokrycia dachu lub fasady budynku uzyskiwanie jednocześnie energii elektrycznej i cieplnej. Uzyskiwane ciepło jest ciepłem niskotemperaturowym. Poszczególne rozwiązania systemów PVT można scharakteryzować ze względu na: różną liczbę...
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Simulation investigation of perovskite-based solar cells
PublicationThree models of thin-layer lead-halide perovskite solar cells with different electron-transport layers (TiO2,SnO2,ZnO) were investigatedby the simulation method. The perovskite layer thickness was optimized for all the systems. The analysis of the standard photovoltaic cell performanceparameters at various operating temperatures was performed. The best performance was achieved for the system with theSnO2conductive layer.
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Featuring Semitransparent p–i–n Perovskite Solar Cells for High-Efficiency Four-Terminal/Silicon Tandem Solar Cells
PublicationTwo issues need to be resolved when fabricating p–i–n semitransparent perovskite solar cells (ST-PVSCs) for four-terminal (4 T) perovskite/silicon tandem solar cells: 1) damage to the underlying absorber (MAPbI3), electron transporting layer ([6,6]-phenyl-C61-butyric acid methyl ester, PCBM), and work function (WF) modifier (polyethylenimine, PEI), resulting from the harsh sputtering conditions for the transparent electrodes (TEs)...
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A novel method for archiving multibeam sonar data with emphasis on efficient record size reduction and storage
PublicationOver the past few years considerable advances in sonar technology, spatial positioning capabilities and computer processing power have lead to significant improvements in mapping, imaging and technologies of seafloor exploration. Recently, modern multibeam echosounder systems (MBES) capable of recording backscatter data for the whole water column, not just for the seabed, have become available thus providing data allowing for...
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High-precision bearing estimation for active sonar with cylindrical array performed by interpolated array transformation
PublicationThe article presents a method for improving the accuracy of bearing in multibeam sonar with a cylindrical array. The antenna’s non-linear shape and the resulting non-uniform sampling of the signal in space, mean that known methods of high-resolution spectral analysis cannot be used. In order to apply an algorithm from this group, a linear virtual antenna must be produced. The paper presents a technique of mapping a cylindrical...
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Optimizing of target detection and tracking processes realized on consoles of passive sonar with linear towed antenna
PublicationThe long-range passive towed sonar was first modernised a few years ago. Building on operator experience over that period, a concept was developed of optimising the tasks performed by sonar operators, and improving forms of imaging to inform about object detection and support object tracking. The concept was implemented and successfully tested during ships’ manoeuvres. The optimisation of operator tasks was designed to keep listening...
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Processing of LiDAR and Multibeam Sonar Point Cloud Data for 3D Surface and Object Shape Reconstruction
PublicationUnorganised point cloud dataset, as a transitional data model in several applications, usually contains a considerable amount of undesirable irregularities, such as strong variability of local point density, missing data, overlapping points and noise caused by scattering characteristics of the environment. For these reasons, further processing of such data, e.g. for construction of higher order geometric models of the topography...
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Acoustic imaging of selected areas of Gdansk Bay with the aid of parametric echosounder and side-scan sonar
PublicationThe article presents and analyses the data recorded during sounding of the Gdansk Bay seabed with the aid of a parametric echosounder and a side-scan sonar. The accuracy of seabed structure examination, as a condition for obtaining valuable results, requires correct configuration of echolocation devices and proper calibration of peripheral devices, such as the survey unit geographical position sensor – GPS, the navigation unit,...
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seafloor characterisation combined approach using multibeam sonar echo signal processing and image analysis
PublicationThe authors propose the approach to seafloor characterisation which relies on the combined, concurrent use of two different techniques: (i) multibeam sonar image analysis and (ii) multibeam seabed echoes processing. The first technique is based on constructing the grey-level sonar images of the seabed extracted from the echoes received in the consecutive soundings. Then, the set of parameters describing the local region of sonar...
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The effect of temperature difference on heat transport in solar cells
PublicationW pracy omówiono wpływ wzrostu temperatury i mechanizm transportu ciepła na drodze przewodzenia w układach hybrydowych PV/T. Wyznaczono współczynniki przewodzenia krystalicznego krzemu typu n i p oraz gęstość strumienia ciepła w zakresie temperatur od 0 do 100 st. C.
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Impact of the trap–assisted recombination in the perovskite solar cells
PublicationTo achieve the highest performance using perovskite solar cells it is necessary to understand all the dominant mechanisms which affect the operation of solar cell. Here, we have investigated the bulk and interface trap–assisted recombination processes in the solar cells with p–i–n architecture. These studies are based on the numerical and experimental methods to get better understanding of these physical processes. The following results...
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Stabalization of solar-panel energy system for Pakistani household
PublicationRenewable energy resources such as Sun and wind are getting popular and easier to use day by day. It is a better method to fulfill our demands as sun is a continuous source of energy for Earth. Many countries are fulfilling their demands by Solar Panels. Solar panel is used as a converter between sunlight and electrical energy. This research paper is going to tell that how to obtain electrical energy from sunlight more efficiently...
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Polymers in High-Efficiency Solar Cells: The Latest Reports
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Photovoltaic solar energy development in the Baltic Sea Region
PublicationInformacje zawarte w tym artykule odzwierciedlają różnorodność rozwoju technologii fotowoltaicznych i różnorodność etapów realizacji PV przez kraje regionu Morza Bałtyckiego (Dania, Finlandia, Niemcy, Łotwa, Litwa, Szwecja, Polska, Estonia).
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Application of splines and wavelets along with TIN decimation to 3D imagingof seafloor from multibeam sonar data
PublicationW pracy przedstawiono dwie metody reprezentacji danych batymetrycznych otrzymanych z pomiarów z użyciem sonaru wielowiązkowego. Reprezentacja przy pomocy funkcji sklejanych jest odpowiednia dla baz danych, podczas gdy reprezentacja z wykorzystaniem funkcji falkowych posiada dobre właściwości kompresyjne.
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MSIS sonar image segmentation method based on underwater viewshed analysis and high-density seabed model
PublicationHigh resolution images of Mechanically Scanned Imaging Sonars can bring detailed representation of underwater area if favorable conditions for acoustic signal to propagate are provided. However to properly asses underwater situation based solely on such data can be challenging for less than proficient interpreter. In this paper we propose a method to enhance interpretative potential of MSIS image by dividing it in to subareas depending...