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Tytuł:
MEMS technology evaluation for submerged vehicle navigation
Autorzy:
Demkowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/331778.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
MEMS
IMU
INS
Opis:
The article undertakes analysis of some vital aspects of inertial navigation using MEMS. Although MEMS inertial sensors offer affordable, scaled units, and though their inherent measurement noise can be relatively easily mitigated, there are still parameters due to which they are not currently capable of meeting all requirements for accurate inertial navigation. The article presents a few aspects of MEMS gyro errors, and their estimation process in the context of INS processing flow. These errors have a serious impact on overall inertial system performance. The results of undertaken researches in that area, and pointing out the main difficulties behind the INS when using a few top MEMS technologies, were presented as well. The paper clearly states, that current MEMS technologies, including sophisticated software, does not fulfil submerged inertial navigation whilst operating in dynamic conditions, due to linear acceleration, affecting gyro performance.
Źródło:
Hydroacoustics; 2017, 20; 35-40
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Submerged objects modeling and storing in a global reference context using multiresolution spline technique
Autorzy:
Demkowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/331973.pdf
Data publikacji:
2015
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
bathymetry
spline interpolation
3D spatial data representation
Opis:
Contemporary sensors i.e. multibeam sonars, 3D shuttle radar topography mission elevation data features high resolution. On the other side bathymetric models of different resolution from different sensors are available as well, starting from very high resolution MBS records as well as low resolution records coming from regular scattered measurement. Approximating and eventually visualizing high volume scattered 3D raster data of different resolution results in some difficulties related to computer processing power. The paper presents some advantages of using multiresolution splines combined with the Hilbert curve approach. The proposed approach consists of two stages: firstly, data of different resolution are interpolated using spline technique and finally the knots and control points are saved using the Hilbert curve. Such an approach especially facilitates high volume spatial data level of details (LoD) visualization technique.
Źródło:
Hydroacoustics; 2015, 18; 47-52
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multibeam sonar records data decimation using hierarchical spline interpolation
Autorzy:
Demkowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/332141.pdf
Data publikacji:
2013
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
Multibeam sonar records feature high vertical and horizontal resolution. Interpolating and approximating and eventually displaying scattered 3D raster data of high volume leads to some difficulties related to a computer processing power. The paper presents some advantages of using hierarchical splines. The proposed approach consists of two stages: firstly, all acquired multibeam sonar raw data are interpolated with high density uniform spline interpolation. The knots and control points of interpolated network are saved for defined resolution level. In the next stage preprocessed high resolution data are combined with low resolution data sets following prior knot decimation process. Such approach allow real time 3D displaying of multibeam sonar data for different zoom levels.
Źródło:
Hydroacoustics; 2013, 16; 41-46
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
MEMS technology quality requirements as applied to multibeam echosounder
Autorzy:
Demkowicz, J.
Bikonis, K.
Powiązania:
https://bibliotekanauki.pl/articles/331722.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
MEMS
IMU
Multibeam Sonar
Opis:
Small, lightweight, power-efficient, and low-cost microelectromechanical system (MEMS) inertial sensors and microcontrollers, available in the market today, help reduce the instability of Multibeam Sonars. Current MEMS inertial measurement units (IMUs) come in many shapes, sizes, and costs — depending on the application and performance required. Although MEMS inertial sensors offer affordable, appropriately scaled units, they are not currently capable of meeting all requirements for accurate and precise attitudes, due to their inherent measurement noise. The article presents the comparison of different MEMS technologies, and their parameters regarding to the main application; namely, Multibeam Echo Sounders (MBES). The MEMS parameters’ quality are crucial for further MBES record- processing, the article presents the results of undertaken researches in that area, and the results are relatively positive for low-cost MEMS.
Źródło:
Hydroacoustics; 2016, 19; 75-82
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
3D imaging of seabed from electronic chart bathymetric data
Autorzy:
Demkowicz, J.
Stepnowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/331740.pdf
Data publikacji:
2001
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
Application of 3D imaging and mapping of seabed is very attractive in many areas including marine cartography, navigation. hydrography, GIS systems etc. There are two competing approaches to constructing 3D images of seabed. The first, off-line method, utilizes the bathymetric information extracted from vectorized digital navigational charts. The second one, on-line technique, employs multibeam sonar seabed echo records processing, The paper describes procedures of bathymetric data analysis for the first method along with newly proposed rendering schemes.
Źródło:
Hydroacoustics; 2001, 4; 37-42
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Data Integration from GPS and Inertial Navigation Systems for Pedestrians in Urban Area
Autorzy:
Bikonis, K.
Demkowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/115987.pdf
Data publikacji:
2013
Wydawca:
Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
Tematy:
Inertial Measurement Unit (IMU)
Urban Area
inertial navigation system (INS)
Global Positioning System GPS
extended Kalman filter (EKF)
pedestrian trajectory
Micro Electro Mechanical Systems (MEMS)
Integration of Navigation
Opis:
The GPS system is widely used in navigation and the GPS receiver can offer long-term stable absolute positioning information. The overall system performance depends largely on the signal environments. The position obtained from GPS is often degraded due to obstruction and multipath effect caused by buildings, city infrastructure and vegetation, whereas, the current performance achieved by inertial navigation systems (INS) is still relatively poor due to the large inertial sensor errors. The complementary features of GPS and INS are the main reasons why integrated GPS/INS systems are becoming increasingly popular. GPS/INS systems offer a high data rate, high accuracy position and orientation that can work in all environments, particularly those where satellite availability is restricted. In the paper integration algorithm of GPS and INS systems data for pedestrians in urban area is presented. For data integration an Extended Kalman Filter (EKF) algorithm is proposed. Complementary characteristics of GPS and INS with EKF can overcome the problem of huge INS drifts, GPS outages, dense multipath effect and other individual problems associated with these sensors.
Źródło:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2013, 7, 3; 401-406
2083-6473
2083-6481
Pojawia się w:
TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Kalman filtering for 3d real time data visualization of multibeam sonar records
Autorzy:
Demkowicz, J.
Moszyński, M.
Powiązania:
https://bibliotekanauki.pl/articles/331515.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
Kalman filtering
sonar records
visualization
Opis:
For the last decade multibeam sonars have been increasingly used for mapping and visualization of the bottom surfaces to provide the 'physical bases' for environmental studies due to theirs unprecedentedly high resolution mapping ability. However, the raw sonar records are subject to systematic errors, random noise and outliers. In this paper Kalman filtering approach to generating optimal estimates of bottom surface from a noisy raw sonar records is presented. The experiment on the surface indicates that after applying the Kalman filtering technique the outliers of raw records can be efficiently detected and removed. Moreover in the same time, the two-step Kalman filtering method is applied, which aims to filter every multibeam sonar swath and enable 3D seabed visualization in real time. The 3D bottom relief before, and after the filtering method application is also presented.
Źródło:
Hydroacoustics; 2003, 6; 189-194
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
EGNOS-Based GNSS receiver for precise positioning in restricted areas
Autorzy:
Demkowicz, J.
Bikonis, K.
Powiązania:
https://bibliotekanauki.pl/articles/331610.pdf
Data publikacji:
2016
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
EGNOS
GNSS
positioning accuracy
Opis:
Positioning accuracy is very important in many areas, whereas the typical GPS receiver accuracy is often not sufficient. The European Geostationary Navigation Overlay Service (EGNOS), Europe’s first venture into satellite navigation, improves the open public service offered by the Global Positioning System (GPS). As a satellite navigation augmentation system, EGNOS improves the accuracy of GPS by providing a positioning accuracy to within 3 meters. In this paper we present GNSS receivers based on EGNOS, dedicated for precise positioning in restricted areas of continental shelf performance. The article presents some results regarding position accuracy, obtained for a few receivers in that context.
Źródło:
Hydroacoustics; 2016, 19; 65-73
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Inertial sensors applications in underwater measurements
Autorzy:
Bikonis, K.
Demkowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/332294.pdf
Data publikacji:
2017
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
inertial measurements unit (IMU)
inertial navigation system (INS)
underwater navigation system
Opis:
Over the past decades microelectromechanical systems (MEMS) researchers have demonstrated a number of microsensors for almost every possible sensing modality, including attitudes. Current MEMS inertial measurement units (IMU) come in many shapes, sizes, and costs — depending on the application, and performance required. MEMS sensors have proved and demonstrated performance exceeding those of their macroscale counterpart sensors. In the paper chosen IMU applications in underwater measurements are presented. First, for reduction of instability of the underwater sensor during measurements, like multibeam echosounder system (MBES), where the MEMS parameters’ quality are crucial for further MBES record-processing. Second, in underwater navigation systems, for determining the position of underwater vehicles, like Remotely Operated Vehicles (ROV) and, more recently, Autonomous Underwater Vehicle (AUV) or to improve other positioning methods.
Źródło:
Hydroacoustics; 2017, 20; 13-18
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application of CDMA modulated signals in seafloor remote sensing
Autorzy:
Demkowicz, J.
Łubiniewski, Z.
Powiązania:
https://bibliotekanauki.pl/articles/332774.pdf
Data publikacji:
2005
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The paper investigates the application of digital modulation access technique called Code Division Multiple Access (CDMA) to remote sensing of a seafloor. In a traditional sonar, the next ping cannot be sent until the echo from previous transmission has been received by the sonar transducer. As a result, such a sonar system is characterized by low duty ratio what causes the decrease of data resolution especially for larger depths. Using the CDMA modulation technique, may reduce pulse repetition rate. In the CDMA technique, each sonar pulse consists of several multiple narrow pulses, where each is encoded with a phase shift 0 or đ based on a spreading code. The paper presents the performance investigation results for this modulation scheme as applied both to transmitted and seafloor backscattered signal. The bottom backscattering was modeled numerically for typical bottom material and morphology. The advantages and constraints of the proposed technique were discussed in the context of echo detection and usefulness in acoustic seafloor characterization.
Źródło:
Hydroacoustics; 2005, 8; 15-22
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
MEMS technology quality requirements as applied to multibeam echosounder
Autorzy:
Bikonis, K.
Demkowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/260431.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
Inertial Measurements Unit
Multibeam Echo Sounder
attitude and heading reference system
motion reference unit
Opis:
Small, lightweight, power-efficient and low-cost microelectromechanical system (MEMS) inertial sensors and microcontrollers available in the market today help reduce the instability of Multibeam Sonars. Current MEMS inertial measurement units (IMUs) come in many shapes, sizes, and costs — depending on the application and performance required. Although MEMS inertial sensors offer affordable and appropriately scaled units, they are not currently capable of meeting all requirements for accurate and precise attitudes, due to their inherent measurement noise. The article presents the comparison of different MEMS technologies and their parameters regarding to the main application, namely Multibeam Echo Sounders (MBES). The quality of MEMS parameters is crucial for further MBES record-processing. The article presents the results of undertaken researches in that area, and these results are relatively positive for low-cost MEMS. The paper undertakes some vital aspect of using MEMS in the attitude and heading reference system (AHRS) context. The article presents a few aspects of MEMS gyro errors and their estimation process in the context of INS processing flow, as well as points out the main difficulties behind the INS when using a few top MEMS technologies.
Źródło:
Polish Maritime Research; 2018, 4; 59-64
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Integration of inertial sensors and GPS system data for underwater navigation
Autorzy:
Bikonis, K.
Demkowicz, J.
Stepnowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/332423.pdf
Data publikacji:
2012
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The Inertial Navigation System (INS) is usually employed to determine the position of an underwater vehicles, like Remotely Operated Vehicles (ROV) and, more recently, Autonomous Underwater Vehicle (AUV). The accuracy of the position provided by the INS, which uses accelerometers and gyroscopes, deteriorates with time. An external aiding sources such as the Global Positioning System (GPS) can be employed to reduce the error growth in the INS. The GPS aided INS system provides enhance positioning accuracy of the underwater vehicles compared to that of a stand-alone INS technique. In the paper integration algorithm of inertial sensors (accelerometers and gyroscopes) and GPS system data for underwater navigation is presented. For data integration algorithm External Kalman Filter (EKF) is proposed.
Źródło:
Hydroacoustics; 2012, 15; 21-26
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
VRML visualization of pelagic fish movement in the echosounder beam
Autorzy:
Moszyński, M.
Bikonis, K.
Demkowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/332747.pdf
Data publikacji:
2003
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
VRML
pelagic
fish
echosounder beam
Opis:
During over thirty years of development of echosounders, the acquisition software has developed different kind of charts for data visualization. In the paper the concept of creation of dynamic echograms from the data acquired in acoustical surveys is presented. As the modern split-beam echosounders allow for nonambiguous localization of targets in the water column, it is possible to visualize them in 3D coordinate system. Virtual Reality Modeling Language VRML is a popular language used in modeling of virtual reality. Using its build-in properties, it is relatively easy to visualize movement of fish treated as an object in any coordinate system. VRML despite the typical application in computer graphics is also used in other various fields. For instance in chemistry it is used for visualization of atom particles, in medicine for modeling of human organs, in astronomy for visualization of trajectories of the stars and in geography and navigation for creation of 3D maps. Hence, in this paper we describe its application in fisheries. Additionally, as the any WWW browser can be equipped with VRML plugin 3D fish visualization can be redistributed in the Internet.
Źródło:
Hydroacoustics; 2003, 6; 53-58
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A Novel approach to bottom scattering using a narrow acoustic beam
Autorzy:
Zieliński, A.
Tegowski, J.
Lubniewski, Z.
Demkowicz, J.
Powiązania:
https://bibliotekanauki.pl/articles/332113.pdf
Data publikacji:
2004
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
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.
Źródło:
Hydroacoustics; 2004, 7; 253-258
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
3D visualisation and monitoring of marine pollutant aggregations in web-based GIS
Autorzy:
Łubiniewski, Z.
Bikonis, K.
Demkowicz, J.
Partyka, A.
Stepnowski, A.
Powiązania:
https://bibliotekanauki.pl/articles/332356.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The paper presents the visualisation and monitoring of marine pollutant aggregations as the sample application of the real-time, remotely accessible marine GIS. The system is dedicated for instantaneous integration, processing and visualisation of marine data acquired by direct sampling, satellite remote sensing and underwater acoustic systems. The developed Web-based GIS is capable of producing 2D maps with overlaid various types of data, as well as generating the composed, time-varying 3D scenes presenting different elements of marine environment. As the sample application of the system, the visualisation of the 3D modelling of an oil spill drift and spreading within the southern Baltic area is presented. The data were obtained from the composed 3D modelling system CAROCS. The developed GIS, due to its remote accessibility and the on-line data processing, may be applied as a useful tool for maritime domain awareness and emergency management supporting, with respect to hazard of a different kind: pollution, ecological catastrophes, natural disasters. The system utilises the SQL spatial database for data storage and the Scalable Vector Graphics (SVG) and Virtual Reality Modelling Language (VRML) standards for remote presentation of geographical objects, and requires only the WWW browser with SVG and VRML viewer on the client side.
Źródło:
Hydroacoustics; 2006, 9; 103-108
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 16

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