Wyniki wyszukiwania - BazTech

1

Application of Shape From Shading Technique for Side Scan Sonar Images

Bikonis K., Moszynski M., Lubniewski Z.

Polish Maritime Research

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2013

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nr 3

39--44

EN

Digital signal processing technology has revolutionized a way of processing, visualisation and interpretation of data acquired by underwater systems. Through many years side scan sonars were one of the most widely used imaging systems in the underwater environment. Although they are relatively cheap and easy to deploy, more powerful sensors like multibeam echo sounders and sonars are widely used today and deliver 3D bathymetry of sea bottom terrain. Side scan sonar outputs data usually in a form of grey level 2D acoustic images but the analysis of such pictures performed by human eye allows creating semi-spatial impressions of seafloor relief and morphology. Hence the idea of post-processing the side scan sonar data in a manner similar to human eye to obtain 3D visualisation. In recently developing computer vision systems the shape from shading approach is well recognized technique. Applying it to side scan sonar data is challenging idea used by several authors. In the paper, some further extensions are presented. They rely on processing the backscattering information of each footprint (pixel in sonar image) along with its surroundings. Additionally, a current altitude is estimated from the size of shadow areas. Both techniques allow constructing 3D representation of sea bottom relief or other investigated underwater objects.

2

A novel method for archiving multibeam sonar data with emphasis on efficient record size reduction and storage

Moszynski M., Chybicki A., Kulawiak M., Lubniewski Z.

Polish Maritime Research

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2013

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nr 1

77--86

EN

Over 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 visualization and analysis of objects other than the seabed such as single fish, fish schools or pollution. Unlike bathymetric sonars, which only capture the seafloor, multibeam systems produce very large amounts of data during surveys. Because of this, storing the data collected during hydrographic or scientific cruises becomes a crucial problem. In this context, the paper proposes a new approach for efficient reduction and storage of MBES records. The results of a sample implementation of the algorithm being tested on several different sets of MBES data are also discussed.

3

Geographic information system for remote integration of diverse under-water acoustic sensor data

Chybicki A., Kamiński Ł., Lubniewski Z., Bruniecki K., Kulawiak M., Dąbrowski J., Moszyński M.

Hydroacoustics

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2009

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Vol. 12

17-24

EN

Maritime and port areas throughout the world are exposed to many different hazards, like pollution, terrorism and natural disasters. Early detection, identification and preparation of appropriate response strategies is especially important in the case of semi-enclosed basins like the Baltic Sea, mainly due to the marine ecosystems' continuous absorption of pollutants including oil, heavy metals and chemicals. Many of those agents are characterised by great toxicity and cause devastation of the natural environment. The huge development in the information technology provides the means and possibilities for much faster and more efficient access to survey data, allowing their remote, nearly real-time management, processing and visualisation. Several approaches and techniques of measurements are available in marine environment monitoring. These consist of direct sampling, airborne and satellite imagery, hydrological measurements using CTD probes, remote sensing with the use of electromagnetic waves, acoustic methods based on the data acquired by multibeam systems, side-scan sonars and singlebeam echosounders.

4

Rozproszony system akwizycji, prezentacji i analizy informacji przestrzennej

Gwaj K., Adamowicz R., Demkowicz J., Lubniewski Z.

Zeszyty Naukowe Wydziału ETI Politechniki Gdańskiej. Technologie Informacyjne

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2006

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T. 10

331-338

PL

W artykule przedstawiono skalowalny system prezentacji danych przestrzennych pochodzących z różnych źródeł, ze szczególnym uwzględnieniem specyfikacji Open Geospatial Consortium (OGC). System został zaimplementowany w technologii .NET i pracuje w środowisku rozproszonym w oparciu o Web Service. Aplikacja zrealizowana jest w formie apletu .NET, dzięki czemu można ją w prosty sposób osadzić w dokumencie HTML i umieścić na serwerze (niestety na razie jedynie Internet Explorer obsługuje aplety .NET), lub uruchomić jako samodzielną aplikację systemu Windows. Zważywszy na ciągły rozwój technologii .NET w przyszłości aplikacja będzie mogła działać również na innych platformach systemowych takich jak Linux, czy Novel.

EN

The paper presents a scaleable, distributed GIS system for the spatial data representation origin from different sources. The application complies with OGC (Open Geospatial Consortium specification. The system is implemented in .NET technology and uses Web Services. The n purpose of the application is an education, however the application is rather technologic advanced.

5

Internetowy portal wspomagający symulacje i analizę sytuacji krytycznych w regionie oraz zespołowe podejmowanie decyzji

Czarnul P., Krawczyk H., Lubniewski Z., Partyka A., Stepnowski A.

Zeszyty Naukowe Wydziału ETI Politechniki Gdańskiej. Technologie Informacyjne

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2006

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T. 10

597-605

PL

Omówiono internetowy portal dostępowy zintegrowanego systemu służącego do analizy sytuacji wyjątkowych, wizualizacji przestrzennej kluczowych obiektów infrastruktury wraz z numerycznymi ocenami różnego typu zagrożeń terrorystycznych lub katastrof naturalnych. Portal zapewnia interakcję pomiędzy rozproszonymi grupami terenowymi oraz centrami zarządzania sytuacjami kryzysowymi, również decydentami, współdzieloną wizualizację wyników symulacji z danymi o zagrożeniach na mapach cyfrowych, możliwość dyskusji i tworzenia projektów rozwiązań w czasie rzeczywistym widzianym przez innych członków zespołu jak również możliwość sprzężenia zwrotnego a więc przekazywania danych do systemu o symulacji potencjalnych ataków. Nowe scenariusze są wizualizowane automatycznie. Autorzy zwrócili szczególną uwagę na bezpieczeństwo, wydajność, niezawodność i przenośność rozwiązania.

EN

The paper discusses a concept of a Web based access portal of an integrated system for critical situation analysis, visualization of spatial and non-spatial data related to key components of the infrastructure including numerical values corresponding to degrees of threats, including terrorist attacks and natural disasters. The portal allows interaction among geographically distributed centers for critical situation analysis and reaction, including decision makers, shared visualization of simulation results and threat data on digital mars. Furthermore, it provides an environment for online real time discussion and drawing designs to assist solutions which are all visible to the members of the group, as well as a communication feedback channel Le. passing input data for new simulations. Results of new scenarios are reflected automatically in the user view. The authors focused especially on security, efficiency, reliability and transferability of the solution.

6

A Novel approach to bottom scattering using a narrow acoustic beam

Zieliński A., Tegowski J., Lubniewski Z., Demkowicz J.

Hydroacoustics

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2004

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Vol. 7

253-258

EN

The acoustic response of the ocean bottom to a probing pulse is a complex and complicated process. This process is influenced by with the form of an acoustic transmitting/receiving beam and by the physical processes involved in sound scattering from the surface and the volume of the ocean bottom. The complexities of these phenomena often obscure an intuitive understanding of the underlying principles of echo formation and its reception. In this paper, we propose a simplistic model for this complex process using filter theory. The bottom is represented as a surface reflector with an acoustic wave front sweeping over it with time-varying velocity. The impulse response of a smooth flat bottom is characteristic of a low pass-filter that will greatly attenuate the impinging high frequency pulse. On the other hand, bottom undulations will modulate the reflected signal such that it can be represented by the impulse response of a band-pass filter. The received echo can be represented as the response of such filter to a high frequency pulse. The characteristics and amplitude of the echo are dependent on frequency spectrum overlap between the transmitted pulse spectrum and the filter frequency response. In the paper, we discuss several cases of interest with the intent to provide a solid intuitive understanding of the echo formation from the system point of view.