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Wyszukujesz frazę "Łubniewski, Z." wg kryterium: Autor


Tytuł:
3D object shape reconstruction from underwater multibeam data and over ground LiDAR scanning
Autorzy:
Kulawiak, M.
Łubniewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/260564.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
multibeam sonar
laser scanning
three dimensional reconstruction
point cloud
triangulation
Opis:
The technologies of sonar and laser scanning are an efficient and widely used source of spatial information with regards to underwater and over ground environment respectively. The measurement data are usually available in the form of groups of separate points located irregularly in three-dimensional space, known as point clouds. This data model has known disadvantages, therefore in many applications a different form of representation, i.e. 3D surfaces composed of edges and facets, is preferred with respect to the terrain or seabed surface relief as well as various objects shape. In the paper, the authors propose a new approach to 3D shape reconstruction from both multibeam and LiDAR measurements. It is based on a multiple-step and to some extent adaptive process, in which the chosen set and sequence of particular stages may depend on a current type and characteristic features of the processed data. The processing scheme includes: 1) pre-processing which may include noise reduction, rasterization and pre-classification, 2) detection and separation of objects for dedicated processing (e.g. steep walls, masts), and 3) surface reconstruction in 3D by point cloud triangulation and with the aid of several dedicated procedures. The benefits of using the proposed methods, including algorithms for detecting various features and improving the regularity of the data structure, are presented and discussed. Several different shape reconstruction algorithms were tested in combination with the proposed data processing methods and the strengths and weaknesses of each algorithm were highlighted.
Źródło:
Polish Maritime Research; 2018, 2; 47-56
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multibeam data processing for 3D object shape reconstruction
Autorzy:
Kulawiak, M.
Łubniewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/332626.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
multibeam sonar
3D reconstruction
point cloud
wrecks
rasterization
Opis:
The technology of hydroacoustic scanning offers an efficient and widely-used source of geospatial information regarding underwater environments, providing measurement data which usually have the structure of irregular groups of points known as point clouds. Since this data model has known disadvantages, a different form of representation based on representing surfaces with simple geometric structures, such as edges and facets, is preferred for data featuring seabed surface relief and various underwater objects. In this paper, the authors propose a multiple-step approach to three-dimensional surface reconstruction from multibeam sonar measurements, relying on the proper application of various algorithms for noise reduction, data rasterization and classification. The results obtained by combining several different surface reconstruction algorithms with the proposed data processing technique were tested, and the strengths and weaknesses of each method were highlighted.
Źródło:
Hydroacoustics; 2017, 20; 105-112
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
On algorithm details in multibeam seafloor classification
Autorzy:
Łubniewski, Z.
Sęk, D.
Powiązania:
https://bibliotekanauki.pl/articles/331668.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
seafloor classification
multibeam sonar
sonar data processing
Opis:
Remote sensing of the seafloor constitutes an important topic in exploration, management, protection and other investigations of the marine environment. In the paper, a combined approach to seafloor characterisation is presented. It relies on calculation of several descriptors related to seabed type using three different types of multibeam sonar data obtained during seafloor sensing, viz.: 1) the grey-level sonar images (echograms) of the 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 sonar beams. The proposed methodology has been tested using field data records acquired from several bottom types in the Southern Baltic Sea. Using the examples of particular parameters, the influence on the specific manner and details regarding their calculation, i.e. the size of the applied current local window to a sonar image, on the obtained classification performance, is discussed.
Źródło:
Hydroacoustics; 2017, 20; 113-120
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Characterizing surface and air temperature in the Baltic Sea coastal area using remote sensing techniques and GIS
Autorzy:
Chybicki, A.
Kulawiak, M.
Łubniewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/963420.pdf
Data publikacji:
2016
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
remote sensing
coastal zone
AVHRR
GIS
surface temperature
air temperature
vegetation index
Opis:
Estimation of surface temperature using multispectral imagery retrieved from satellite sensors constitutes several problems in terms of accuracy, accessibility, quality and evaluation. In order to obtain accurate results, currently utilized methods rely on removing atmospheric fluctuations in separate spectral windows, applying atmospheric corrections or utilizing additional information related to atmosphere or surface characteristics like atmospheric water vapour content, surface effective emissivity correction or transmittance correction. Obtaining accurate results of estimation is particularly critical for regions with fairly non-uniform distribution of surface effective emissivity and surface characteristics such as coastal zone areas. The paper presents the relationship between retrieved land surface temperature, air temperature, sea surface temperature and vegetation indices (VI) calculated based on remote observations in the coastal zone area. An indirect comparison method between remotely estimated surface temperature and air temperature using LST/VI feature space characteristics in an operational Geographic Information System is also presented.
Źródło:
Polish Maritime Research; 2016, 1; 3-11
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Comparison of direct and inverse methods of satellite observations downscaling for the coastal zone area
Autorzy:
Chybicki, A.
Łubniewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/331736.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
Earth observation
land surface temperature
sea surface temperature
PBIM downscaling method
surface effective emissivity
Opis:
The Earth observation satellite imaging systems have known limitations, especially regarding their spatial and temporal resolution. Therefore, approaches which aim to combine data retrieved from sensors of higher temporal and lower spatial resolution with the data characterized by lower temporal but higher spatial resolution are of high interest. This allows for joint utilization of the advantages of both these types of sensors. As there are several ways to achieve this goal, in this paper two approaches, direct and inverse, of downscaling the land surface temperature (LST) derived from low resolution imagery acquired by the Advanced Very High Resolution Radiometer (AVHRR) were evaluated. The applied downscaling methods utilize biophysical properties of the surface sensed using short wave infrared and thermal band. The presented algorithm evaluation was performed on the basis of a specific test case: the coastal zone area of the Gulf of Gdańsk, Poland. In this context, the objective presented in the study was to compare two methods of downscaling for a specific test case in order to evaluate how the proposed approaches cope with the specific conditions of the coastal zone area.
Źródło:
Hydroacoustics; 2016, 19; 55-64
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Methods for quality improvement of multibeam and LiDAR point cloud data in the context of 3D surface reconstruction
Autorzy:
Kulawiak, M.
Łubniewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/332451.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
multibeam sonar
LiDAR
3D
point cloud
shape reconstruction
noise reduction
Opis:
Point cloud dataset is the transitional data model used in several marine and land remote-sensing applications. During further steps of processing, the transformation of point cloud spatial data to more complex models containing higher order geometric structures like edges and facets may be possible, if an appropriate quality level of input data is provided. Point cloud datasets usually contain 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, processing such data can be quite problematic, especially in the field of object detection and threedimensional surface reconstruction. This paper is focused on applying the proposed methods for reducing the mentioned irregularities from several datasets containing 3D point clouds acquired by multibeam sonars and LiDAR scanners. The article also presents the results obtained by each method, and discusses their advantages.
Źródło:
Hydroacoustics; 2016, 19; 251-258
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Potential of Polish R&D industry in the context of prototyping, design, development and control of a dedicated national satellite SAR system for marine ecosystem monitoring Technical paper - preliminary study
Autorzy:
Chybicki, A.
Łubniewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/332762.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
SAR
satellite
system
observations
maritime
Opis:
Space technology is currently one of the most important elements in the advance of information societies and knowledge-based economies all over the world. The European Space Agency (ESA) is in the focal point of European space activities, while the European Union provides strong financial support for the development of space technologies and applications in its flagship programs. In a domestic scope, the Polish Space Agency (POLSA) is a national aeronautics entity responsible for activities related to development of technologies of the national space sector. Recently, one of the activities which POLSA aims to establish, is the programme of building a system of satellite SAR observations dedicated for Polish users; such as administration, civilian services, and Polish scientific and research entities, that would expand potential use of satellite technologies among numerous Polish beneficiaries. In the context mentioned above, the paper describes the architecture and functional components of an exemplary satellite SAR system, along with the potential of Polish entities to develop such technology.
Źródło:
Hydroacoustics; 2016, 19; 49-54
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reconstruction methods for 3D underwater objects using point cloud data
Autorzy:
Kulawiak, M.
Łubniewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/332592.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
visualizing underwater objects
3D model
shipwrecks imaging
Opis:
Existing methods for visualizing underwater objects in three dimensions are usually based on displaying the imaged objects either as unorganised point sets or in the form of edges connecting the points in a trivial way. To allow the researcher to recognise more details and characteristic features of an investigated object, the visualization quality may be improved by transforming the unordered point clouds into higher order structures. There are many algorithms for constructing meshes from point clouds, some of which are more suited to processing data obtained from particular sources. This article presents the application of several methods for generating 3D models from point clouds for the purpose of reconstructing underwater objects, such as shipwrecks. The article presents the results obtained with each method and discusses possible ways of improving the quality of produced meshes.
Źródło:
Hydroacoustics; 2015, 18; 95-102
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
3D imaging of underwater objects using multibeam data
Autorzy:
Kulawiak, M.
Łubniewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/332737.pdf
Data publikacji:
2014
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
One of the main applications of multi-beam sonars is high-resolution bathymetry measurement, as well as the detecting and imaging of underwater objects, such as shipwrecks. In order to ensure that the visual quality is good enough for the researcher to investigate the object in more detail, an approach relying on the construction of the threedimensional model of an imaged object – e.g. consisting of nodes, edges and plane elements (facets) – is needed. Preceded by the short State-of-the-Art review, the applications of selected algorithms for three-dimensional seafloor-surface and underwater-object shape reconstruction have been presented. Two types of algorithms were investigated in the context of real-time application possibility; namely, raster height map, as well as 2D Delaunay triangulation. The presented preliminary results are promising both with respect to reconstructed 3D shape quality and to algorithm computational complexity, allowing for realtime mode applications.
Źródło:
Hydroacoustics; 2014, 17; 123-128
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A novel method for archiving multibeam sonar data with emphasis on efficient record size reduction and storage
Autorzy:
Moszynski, M.
Chybicki, A.
Kulawiak, M.
Lubniewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/260572.pdf
Data publikacji:
2013
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
sonar
compression
storage
reduction
efficiency
Opis:
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.
Źródło:
Polish Maritime Research; 2013, 1; 77-86
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of satellite imagery and GIS tools for land surface temperature estimation and verification
Autorzy:
Chybicki, A.
Łubniewski, Z.
Niedzielko, J.
Ruciński, D.
Powiązania:
https://bibliotekanauki.pl/articles/331533.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
Land surface temperature (LST) plays an important role in many land-surface processes on regional as well on global scales. It is also a good indicator of energy flux phenomena and is used as a parameter in various Earth observation related studies. However, LST estimation based on processing and utilisation of satellite derived data constitutes several problems in terms of time limitations, accessibility, atmospheric influence etc. The aim of the study was to verify and compare the algorithms especially in the context of minimalisation of errors in LST estimation by satellite observation using various means of GIS data processing and integration. Also, the indirect verification of the LST estimation methods, based on the utilisation of statistics and dependencies of LST, NDVI and air temperature values has been presented and discussed. The presented work has the form of a case study, and due to limited amount of verification data used in the current stage of the investigation, the results should be treated as preliminary. The developed GIS solution for integrating spatial data from many sources needed in the course of this study is also presented.
Źródło:
Hydroacoustics; 2013, 16; 19-28
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of Shape From Shading Technique for Side Scan Sonar Images
Autorzy:
Bikonis, K.
Moszynski, M.
Lubniewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/258963.pdf
Data publikacji:
2013
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
side scan sonar data processing shape from shading
Opis:
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.
Źródło:
Polish Maritime Research; 2013, 3; 39-44
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Reconstruction of 3D shape from sidescan sonar images using shape from shading technique
Autorzy:
Moszyński, M.
Bikonis, K.
Łubniewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/332701.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
Side scan sonar (SSS) is one of the most widely used imaging systems in the underwater environment. It is relatively cheap and easy to deploy in comparison with more powerful sensors like multibeam echosounder or synthetic aperture sonar. Although, the SSS does not provide directly the seafloor bathymetry measurements. Its outputs are usually in a form of grey level acoustic images of seafloor. However, the analysis of such images performed by human eye allows creating semi-spatial impressions on seafloor relief and morphology. The 3D shape reconstruction from 2D images using SFS approach is one of classical problems in computer vision. In the paper, the method based on Shape From Shading (SFS) technique for SSS images processing is presented. The 3D seafloor relief is reconstructed using the information from both the currently processed and previous ping. The seafloor backscattering coefficient dependence on an incident angle, which is needed in the applied SFS algorithm scheme, is being estimated in the experimental way, i.e. by analysis of SSS image contents for the flat seabed region.
Źródło:
Hydroacoustics; 2013, 16; 181-188
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Using principal component analysis and canonical discriminant analysis for multibeam seafloor characterisation data
Autorzy:
Łubniewski, Z.
Stepnowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/331872.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The paper presents the seafloor characterisation based on multibeam sonar data. It relies on using the integrated model and description of three types of multibeam 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 sonar beams. The classification is performed by utilisation of several statistical methods applied for analysis of a set of seafloor descriptors derived from multibeam data. In the paper, the use of Principal Component Analysis (PCA), as well as Canonical Discriminant Analysis (CDA) for reduction of the seafloor parameter space dimension is presented along with the obtained results. In addition, the use of the open source World Wind Java SDK tool for implementation of imaging and mapping of seafloor multibeam data, integrated with other elements of a scene and overlaid on rich background data, is also shown.
Źródło:
Hydroacoustics; 2012, 15; 123-130
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Seafloor characterisation using multibeam data: sonar image properties, seabed surface properties and echo properties
Autorzy:
Łubniewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/331826.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
In the paper, the approach to seafloor characterisation is presented. The multibeam sonars, besides their well verified and widely used applications like high resolution bathymetry and underwater object detection and imaging, are also the promising tool in seafloor characterization and classification, having several advantages over conventional single beam echosounders. The proposed approach relies on the combined, concurrent use of several techniques of multibeam sonar data processing. The first one is based on constructing the grey-level sonar images of seabed using the backscattering strength calculated for the echoes received in the consecutive beams. Then, the set of parameters describing the local region of sonar image is calculated. These include both the first and the second order statistics of the grey level, and the texture analysis. The second technique utilises the 3D model of the seabed surface, which is constructed as a set of (x, y, z) points using the detected bottom range for each beam in the multibeam system seafloor imaging procedure. For the local region of seabed surface, the descriptors like rms height and autocorrelation radius are calculated. The third technique assumes the use of a set of parameters of the multibeam echo envelope, similarly as in single beam classification. The parameters include echo energy and its statistics, as well as the set of echo shape descriptors, and are calculated for each beam allowing the estimation of their dependence on seafloor incident angle. Then, for selected parameters, the characteristic features quantitatively describing their angular dependence, like slope, or range, are calculated. Finally, the features obtained by these 3 techniques have been combined together and used in seabed supervised classification procedure based on standard classifiers. The proposed method has been tested using multibeam data records acquired from several bottom types in the Gulf of Gdańsk region. The obtained results show that application of the proposed combined approach improves the classification comparison with those of using only the one scheme of seafloor multibeam data processing.
Źródło:
Hydroacoustics; 2011, 14; 135-142
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł

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