Wyniki wyszukiwania - BazTech

1

Mapping South Baltic near-shore bathymetry using sentinel-2 observations

Chybicki A.

Polish Maritime Research

|

2017

|

nr 3

15--25

EN

One of the most promising new applications of remote observation satellite systems (RO) is the near-shore bathymetry estimation based on spaceborn multispectral imageries. In recent years, many experiments aiming to estimate bathymetry in optically shallow water with the use of remote optical observations have been presented. In this paper, optimal models of satellite derived bathymetry (SDB) for relatively turbid waters of the South Baltic Sea were presented. The obtained results were analysed in terms of depth error estimation, spatial distribution, and overall quality. The models were calibrated based on sounding (in-situ) data obtained by a single-beam echo sounder, which was retrieved from the Maritime Office in Gdynia, Poland. The remote observations for this study were delivered by the recently deployed European Space Agency Sentinel-2 satellite observation system. A detailed analysis of the obtained results has shown that the tested methods can be successfully applied for the South Baltic region at depths of 12-18 meters. However, significant limitations were observed. The performed experiments have revealed that the error of model calibration, expressed in meters (RMSE), equals up to 10-20% of the real depth and is, generally, case dependent. To overcome this drawback, a novel indicator of determining the maximal SDB depth was proposed. What is important, the proposed SDB quality indicator is derived only on the basis of remotely registered data and therefore can be applied operationally.

2

Characterizing surface and air temperature in the Baltic Sea coastal area using remote sensing techniques and GIS

Chybicki A., Kulawiak M., Łubniewski Z.

Polish Maritime Research

|

2016

|

nr 1

3--11

EN

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.

3

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

Chybicki A., Łubniewski Z.

Hydroacoustics

|

2016

|

Vol. 19

49--54

EN

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.

4

Comparison of direct and inverse methods of satellite observations downscaling for the coastal zone area

Chybicki A., Łubniewski Z.

Hydroacoustics

|

2016

|

Vol. 19

55--64

EN

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.

5

Coastline change-detection method using remote sensing satellite observation data

Markiewicz Ł., Mazurek P., Chybicki A.

Hydroacoustics

|

2016

|

Vol. 19

277—284

EN

Coastal zones are not only the fundaments for local economics based on trade, shipping and transport services, but also a source of food, energy, and resources. Apart from offering diverse opportunities for recreation and tourism, coastal zones provide protection against storms and other meteorological disturbances. Environmental information is also essential because of the direct influence on a country’s maritime zones, which are territorial sea and exclusive economic zones. Keeping local communities and ecosystems healthy requires monitoring and assessing of all the vital changes of territorial sea and its baseline. The paper presents a method and a concept of a system that provides an efficient means of automatic analysis of spatial data provided by satellite observation systems (optical Landsat 8 and SAR Sentinel 1) in order to monitor, and detect, changes in the coastline. The proposed methodology is based on a set of algorithms that enable one to trace and detect changes in coastline shape, and eventual damage to marine infrastructure, such as breakwaters and harbours, relying on high resolution satellite observational products.

6

Calibration of precipitation estimation algorithm with particular emphasis on the Pomeranian region using high performance computing

Bieliński T., Chybicki A.

Hydroacoustics

|

2016

|

Vol. 19

17--26

EN

Fast and accurate precipitation estimation is an important element of remote atmosphere monitoring, as it allows, for example, to correct short-term weather forecasts and the prediction of several types of meteorological threats. The paper presents methodology for calibrating precipitation estimation algorithm based on MSG SEVIRI sensor data, and Optimal Cloud Analysis product available via EumetCast transmission. Calibration is performed in a predefined coastal zone area, and utilizes the parallelized gradient computing method. In order to perform and validate results of estimation, reference weather radar data was provided by the Meteorology and Hydrology Research Institute (pol. Instytut Meteorologii i Gospodarki Wodnej - IMGW). The research was conducted using the Tryton supercomputer - the high performance computing environment of Gdansk University of Technology.

7

Coastal zone monitoring using SENTINEL-1 SAR polarimetry data

Chybicki A., Markiewicz Ł.

Hydroacoustics

|

2015

|

Vol. 18

25--32

EN

In recent years the role of the surveillance and security of Polish boundaries has significantly increased. Polish coastal zone monitoring requires various approaches using various technological means in order to ensure the protection of Polish boundaries. In this paper, the authors discuss and present alternatives to underwater surveillance methods of coastal area analysis and monitoring using data retrieved from the newly developed and operational Synthetic Aperture Radar (SAR) Sentinel-1 (ESA S-1) satellite. The authors discuss whether the proposed data source is a valid and reliable source of data that can be utilized in the current Polish coastline monitoring strategy and increase the safety of the country. A description of the various parameters concerning the data for the sea surface, sea objects and technical infrastructure are also discussed and presented.

8

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

|

2013

|

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.

9

Application of satellite imagery and GIS tools for land surface temperature estimation and verification

Chybicki A., Łubniewski Z., Niedzielko J., Ruciński D.

Hydroacoustics

|

2013

|

Vol. 16

19--28

EN

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.

10

Using phase of short-term Fourier transform for evaluation of spectrogram performance

Czarnecki K., Moszyński M., Chybicki A.

Hydroacoustics

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2011

|

Vol. 14

23-28

EN

The concept of spectrogram performance evaluation which exploits information on phase of short-term Fourier transform (STFT) is presented. A spectrograph which is a timefrequency analyzing tool, is compared to a filter bank that demultiplexes a signal. Local group delay (LGD) and channelized instantaneous frequency (CIF) is obtained for each filtered component signal. In presented solution the performance is evaluated using so-called length of weighted average of reassignment vectors (WARV length). Orthogonal components of each reassignment vector are calculated using above mentioned parameters.

11

Wykorzystanie technologii CUDA do kompresji w czasie rzeczywistym danych pochodzących z sonarów wielowiązkowych

Chybicki A., Laskowski K., Muszyński M.

Zeszyty Naukowe Wydziału ETI Politechniki Gdańskiej. Technologie Informacyjne

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2010

|

T. 19

127-132

PL

W pracy przedstawiono projekt oraz implementację systemu przeznaczonego do kompresji danych z sonarów wielowiązkowych działającego z wykorzystaniem technologii CUDA. Omówiono oraz zastosowano metody bezstratnej kompresji danych oraz techniki przetwarzania równoległego. Stworzoną aplikację przetestowano pod kątem szybkości i stopnia kompresji oraz porównano z innymi rozwiązaniami umożliwiającymi kompresję tego typu informacji.

EN

Recently, multibeam echosounders capable of logging, not only bathymetry focused data, but also the full water-column information have become available. Unlike using bathymetric multibeam sonars, which only capture the seafloor, utilizing full water-column multibeam systems capabilites results in acquiring very large data sets during hydrographic or scientific cruises. The paper presents the concept of algorithms dedicated for reduction of multibeam sonar datasets based on aplying multi-threaded architecture implemented in Graphical Processing Units (GPU). We presented the advantages of utilizing nVdia CUDA technology in the context of efficiency of compression and obtained data reduction ratio.

12

Using wavelet techniques for multibeam sonar bathymetry data compression

Chybicki A., Łubniewski Z., Moszyński M.

Hydroacoustics

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2010

|

Vol. 13

31-38

EN

Multibeam sonars are widely used in applications like high resolution bathymetry measurements or underwater object imaging. One of the significant problems in multibeam sensing of the marine environment is large amount of data which must be transmitted from the sonar processing unit to an operator station using a limited bit rate channel. For instance, such a situation would be in the case when the multibeam sonar was mounted on the autonomous underwater vehicle operating on large depths and transmitting the data to the operator station using acoustic channel. In this context, the authors propose a method for multibeam sonar data size reduction. It relies on the use of wavelet decomposition technique combined with run-length and Huffman coding. The method was applied for lossy compression of raw bathymetry data which had been generated by a multibeam sonar processing unit in a form of a set of points in three-dimensional space. The performed tests revealed that without introducing the substantial distortion into the processed bathymetry data, the proposed approach allows to obtain better compression ratios than in the case of using standard lossy JPEG-like compression techniques.

13

Seafloor characterisation using multibeam sonar echo signal processing and image analysis

Łubniewski Z., Stepnowski A., Chybicki A.

Hydroacoustics

|

2010

|

Vol. 13

171-176

EN

The 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 the slope of a local autocorrelation function of a grey level, are calculated. The second technique assumes the use of a set of parameters of the multibeam echo envelope, similarly as in single beam classification. For selected parameters, namely, for echo envelope moment of inertia and for echo envelope fractal dimension, the slope of their angular dependence is calculated. Finally, the quantities obtained by these 2 techniques have been combined together and the multidimensional distributions of sets of them have been analysed in the context of seabed classification procedure. The approach has been tested using multibeam data records acquired from several bottom types in the Gulf of Gdańsk region. The preliminary results show that application of the proposed combined approach should improve the classification performance in comparison with that of using only the one scheme of seafloor multibeam data processing.

14

Algorytmy analizy, przetwarzania i wizualizacji danych z sonaru wielowiązkowego w rozproszonych systemach GIS

Chybicki A., Kulawiak M., Kamiński Ł., Łubniewski Z., Dąbrowski J.

Polish Hyperbaric Research

|

2009

|

nr 1(26)

19-26

PL

Katedra Systemów Geoinformatycznych prowadzi badania naukowe związane z zastosowaniem nowych technologii implementacji Systemów Informacji Przestrzennej (GIS) w różnych zastosowaniach, a szczególnie w aplikacjach związanych z obszarami morskimi. Prowadzone są też prace badawcze związane z analizą i przetwarzaniem danych dla systemów GIS, ze szczególnym uwzględnieniem danych otrzymywanych z sonarów wielowiązkowych. Niniejszy artykuł stanowi ogólny opis prac badawczych związanych z telemonitoringiem morskim prowadzonych w Katedrze Systemów Geoinformatycznych Politechniki Gdańskiej.

EN

Research carried out by The Department of Geoinformatics of Gdansk University of Technology focuses on processing, analysis and visualization of information related to marine and land environment. In particular, the research activities include: Web-based interactive Geographical Information Systems (GIS), 3D imaging of underwater objects using intelligent methods of recognition and mapping of seafloor, acoustic monitoring and population assessment of marine living resources. This paper describes the most important directions of the Department's research activity in the context of marine habitat monitoring.

15

Sea floor classification using multibeam sonar

Łubniewski Z., Chybicki A.

Hydroacoustics

|

2009

|

Vol. 12

127-132

EN

The paper presents the method of seabed identification and classification using multibeam sonar echoes. The proposed approach is based on calculation of a set of parameters of an echo envelope. The parameters are extracted for each consecutive beam allowing the estimation of their dependence on the seafloor incident angle, and then the relation between seabed type and calculated echo parameters and its angular dependence is investigated. The paper concerns the experiment which has been carried out in Gdansk Bay in November 2008, and some comparisons of the results with those obtained during previous experiment in September 2007. The results for several bottom types are presented and discussed. It was confirmed that the information extracted from multibeam seafloor sensing data, e.g. "water column" recordings, may be useful in seafloor characterisation.

16

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

|

2009

|

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.

17

System GIS do analizy i wizualizacji zanieczyszczeń oraz innych składników środowiska morskiego

Chybicki A., Dąbrowski J., Kulawiak M., Łuba M., Łubniewski Z., Moszyński M., Partyka A., Stepnowski A.

Zeszyty Naukowe Wydziału ETI Politechniki Gdańskiej. Technologie Informacyjne

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2008

|

T. 15

111-116

PL

W artykule przedstawiono koncepcję oraz prototyp morskiego systemu GIS do zdalnego monitorowania w czasie rzeczywistym zanieczyszczeń środowiska morskiego. System pozwala na gromadzenie i integrowanie danych dotyczących zanieczyszczeń, pozyskiwanych za pomocą różnego rodzaju sensorów (echosondy jednowiązkowe, sonary boczne, echosondy wielowiązkowe), jak również zdjęć satelitarnych i lotniczych. Zadaniem systemu jest wizualizacja, także trójwymiarowa, oraz mapowanie zanieczyszczeń, takich jak plamy ropy naftowej, oraz wieloaspektowe przetwarzanie i analiza tych danych. Prezentowany system wykorzystuje technologię ArcSDE do przesyłania i przechowywania danych o charakterze wektorowym i rastrowym oraz komponenty GlobeControl i Map-Control z platformy ArcGIS Engine do prezentacji obiektów na wielowarstwowych mapach dwu- i trójwymiarowych.

EN

Pollution detection, environment sensing and appropriate response strategies are important due to the marine ecosystems' continuous absorption of pollutants of various origins. Several approaches and techniques of measurements are available for marine environment monitoring including direct sampling, airborne and satellite imagery and underwater acoustics. The huge development in the information technology has provided the possibilities for much faster and more efficient access to survey data, allowing their remote, nearly real-time management, processing and visualization. The proposed GIS is able to integrate many different types of marine pollution survey data, especially those acquired by various acoustic sensors like Multibeam Sonar Systems (MBSS), echosounder and Side Scan Sonars (SSS). It also supports instantaneous 2D and 3D visualization in the form of thematic layers that can be overlaid. The system utilises the ArcSDE application server that facilitates storing and managing spatial data (raster, vector, and survey) in a database and ArcGIS Engine GlobeControl and MapControl components for georeferenced presentation of various objects. The set of geoprocessing and spatial analysis methods can be used in order to retrieve relevant information and analysis results.

18

Metody przetwarzania danych pochodzących z sonarów wielowiązkowych dla potrzeb kompresji

Chybicki A., Moszyński M.

Zeszyty Naukowe Wydziału ETI Politechniki Gdańskiej. Technologie Informacyjne

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2008

|

T. 15

207-212

PL

Jednym z najczęściej używanych urządzeń służących do szeroko rozumianego telemonitoringu morskiego są sonary wielowiązkowe (ang. Multibeam systems - MBS). Ich wysoka wydajność w tworzeniu informacji o obiektach znajdujących się pod wodą skutkuje w dużych ilościach danych pozyskiwanych podczas rejsów badawczych i pomiarowych. W tym kontekście, proces przechowywania i zarządzania takim magazynem danych staje się istotnym problemem w badaniach związanych z teleominitoringiem morskim. W artykule przedstawiono szereg metod przetwarzania danych pochodzących z sonarów wielowiązkowych, które mogą być zastosowane dla celów kompresji danych przy jednoczesnym usuwaniu informacji nadmiarowych. Pod uwagę wzięto specyficzny charakter uzyskiwanych danych oraz zastosowano wybrane techniki kompresji sygnałowej i obrazowej.

EN

High efficiency of multibeam sonar system (MBS) hardware due to operational requirements (i.e. high frequency, high ping rate and high resolution of collected data) results in very large volumes of datasets stored on local hard drives of operator's station. In this context, the process of archiving of such warehouse of data collected in acoustic surveys becomes a crucial problem. The paper investigates various lossy and lossless compression methods that can be applied to multibeam sonar data to reduce the size of acquired fi1es without loosing relevant information. The specific character of MBS data allows applying various signal, image and video compression methods to achieve better results than when using standard ones. Various techniques of reordering the data were analyzed to achieve best possible compression ratio.

19

Klasyfikacja dna morskiego na podstawie kątowej zależności cech echa z sonaru wielowiązkowego

Łubniewski Z., Chybicki A.

Zeszyty Naukowe Wydziału ETI Politechniki Gdańskiej. Technologie Informacyjne

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2008

|

T. 15

135-140

PL

Przedstawiono metodę rozpoznawania i klasyfikacji rodzaju dna morskiego opartą na przetwarzaniu echa z sonaru wielowiązkowego. Metoda ta polega na obliczaniu zbioru parametrów obwiedni ech dla poszczególnych wiązek, podobnie jak w metodach wykorzystujących echosondy jednowiązkowe. Następnie estymowana jest zależność wartości poszczególnych parametrów od kąta wiązki oraz badane jest powiązanie otrzymanej zależności z rodza-jem dna morskiego, pod kątem użyteczności w klasyfikacji. W artykule przedstawiono i przedyskutowano wyniki otrzymane dla danych hydroakustycznych zebranych w rejonie Zatoki Gdańskiej dla kilku rodzajów dna.

EN

The method of seabed identification and classification from multibeam sonar echoes is presented. The proposed approach is based on calculation of a set of parameters of an echo envelope, similarly as in seafloor classification using single beam echo sounder. These parameters are extracted for each consecutive beam allowing the estimation of their dependence on the seafloor incident angle. The relation between seabed type and calculated echo parameters and its angular dependence, is investigated. The results obtained using sonar data records from several bottom types in Gdańsk Bay water region are presented and discussed.

20

Dedykowane sieciowe technologie SIP dla prezentacji pseudodynamicznych danych geoprzestrzennych

Kulawiak M., Łuba M., Chybicki A.

Zeszyty Naukowe Wydziału ETI Politechniki Gdańskiej. Technologie Informacyjne

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2008

|

T. 15

117-122

PL

Sieciowe technologie prezentacji danych przestrzennych przeżywają aktualnie rozkwit spowodowany między innymi spadającymi cenami sprzętu komputerowego. Wynikający z tego wzrost wydajności domowych i biurowych stacji roboczych pozwala na praktyczne zastosowanie czasochłonnych algorytmów wizualizacji i przetwarzania skomplikowanych danych rastrowych i wektorowych. Niniejszy artykuł omawia wybrane technologie sieciowej prezentacji danych przestrzennych pod kątem przydatności w procesie tworzenia interaktywnych internetowych aplikacji SIP. Przedstawione technologie, takie jak ESRI ArcIMS oraz należący do domeny Open Source GeoServer zostały porównane pod względem możliwości, stabilności jak również ogólnej wydajności podczas udostępniania sporych rozmiarów danych geoprzestrzennych.

EN

Recently, Web-based Geographic Information Systems related research and its applications have been making rapid progress. Computers with fast processing units and large amounts of memory allow for practical applications of time consuming and resource intensive algorithms, both for spatial analysis as well as visualization of large-volume data such as high resolution raster images, DTM and vector data. However, most Web-based Geographic Information Systems are used for presentation of static data, while the area of dynamic and semi-dynamic data visualization has been mostly neglected. Novel applications of known devices and models such as synthetic aperture radar and oil spill simulations require interactive data presentation, which up until now has been mostly realized using standalone applications or thick web clients. This paper describes a number of Web-based GIS technologies for presentation of semi-dynamic geographic information retrieved from made different sources. It also describes the possibilities these technologies provide for publishing interactive geospatial data such as oil spill spread animation overlaid on background data (eg. terrain elevation data, satellite imagery) and presented in a geographic context. Web-GIS technologies like ESRI ArcIMS (Arc Internet Map Server) and Open Source Geoserver with OpenLayers client library were compared during the research. The paper presents their corre-sponding capabilities, interactive geographic information presentation efficiency as well as general performance when serving considerable amounts of data.