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Tytuł:
DOA Estimation of Ultrasonic Signal by Indirect Phase Shift Determination
Autorzy:
Kreczmer, Bogdan
Powiązania:
https://bibliotekanauki.pl/articles/31339749.pdf
Data publikacji:
2024
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
direction of arrival
signal phase
sonar
ultrasonic range finder
Opis:
The paper presents the concept of the method of determining the direction of ultrasonic signal arrival, i.e., the azimuth and elevation angles. This method is an extension of the previous approach which was proposed to determine only the azimuth angle. The approach is based on the indirect phase determination. This makes it possible to tolerate spacing of receivers greater than half the wavelength of the received signal. At the same time, it provides increased measurement accuracy and reduced hardware requirements. To check the robustness of the method, simulations were carried out for the geometric arrangement of the receivers of the sonar module, for which the method was then implemented. This sonar module was used in the conducted experiments. The results of these simulations and experiments are included in the paper and discussed.
Źródło:
Archives of Acoustics; 2024, 49, 1; 107-120
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Model systemu detekcji przeszkód i mapowania środowiska dla autonomicznych pojazdów podwodnych
Simulation Model of Obstacle Detection and Mapping System for AUVs
Autorzy:
Kot, Rafał
Piskur, Paweł
Sigiel, Norbert
Powiązania:
https://bibliotekanauki.pl/articles/27312466.pdf
Data publikacji:
2023
Wydawca:
Sieć Badawcza Łukasiewicz - Przemysłowy Instytut Automatyki i Pomiarów
Tematy:
detekcja przeszkód
akwizycja danych
przetwarzanie zobrazowań sonarowych
autonomiczny pojazd podwodny
sonar
obstacle detection
data acquisition
sonar image processing
autonomous underwater vehicle
AUV
Opis:
W artykule przedstawiono model systemu detekcji przeszkód i mapowania środowiska, bazujący na przetwarzaniu obrazowym w czasie rzeczywistym, przeznaczony dla autonomicznego pojazdu podwodnego. Model został zrealizowany w oparciu o parametry pracy rzeczywistego sonaru z mechanicznym przestawianiem wiązki Tritech Micron Sonar. Działanie systemu detekcji zostało zweryfikowane z wykorzystaniem matematycznego modelu autonomicznego pojazdu podwodnego poruszającego się w środowisku podwodnym wyrażonym mapą testową przygotowaną na bazie rzeczywistych pomiarów zrealizowanych za pomocą ww. sonaru. Model systemu pozwala wykrywać i zapisywać w postaci mapy, przeszkody znajdujące się w polu widzenia sonaru w czasie rzeczywistym.
This article presents a real-time model of an obstacle detection and environmental mapping system based on image processing for an autonomous underwater vehicle (AUV). The model was based on Tritech Micron Sonar operating parameters with mechanical beam adjustment. The operation of the detection system was verified using a mathematical model of an autonomous underwater vehicle moving in the underwater environment, expressed by a test map prepared based on actual measurements of the above-mentioned sonar. The system model allows for detecting and mapping obstacles in the sonar’s field of view in real-time.
Źródło:
Pomiary Automatyka Robotyka; 2023, 27, 4; 19--26
1427-9126
Pojawia się w:
Pomiary Automatyka Robotyka
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Noise effect on parameters of quiet sonar with code modulation
Autorzy:
Salamon, Roman
Marszal, Jacek
Jedel, Andrzej
Powiązania:
https://bibliotekanauki.pl/articles/24201997.pdf
Data publikacji:
2023
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
silent sonar
maximum length sequence
signal-to-noise ratio
frequency modulation
cichy sonar
sekwencje o maksymalnej długości
stosunek sygnału do szumu
modulacja częstotliwości
Opis:
Earlier publications of the paper authors have shown that the use of code keying mixed with the CW FM sound signal allows the significant reduction in the distance measurement error, compared to classic silent CW FM sonar. In addition to the code modulation parameters, the magnitude of this error is influenced by the received input acoustic noise. The article shows the dependence of the input signal-to-noise ratio and the sound signal parameters on the target distance measurement error and the detection conditions, such as the output signal-to-noise ratio and the side lobe level. The results of the analysis were compared to the same parameters of the CW FM silent sonar without code modulation.
Źródło:
Vibrations in Physical Systems; 2023, 34, 1; art. no. 2023109
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Using SVM Classifier and Micro-Doppler Signature for Automatic Recognition of Sonar Targets
Autorzy:
Saffari, Abbas
Zahiri, Seye Hamid
Khozein Ghanad, Navid
Powiązania:
https://bibliotekanauki.pl/articles/31339922.pdf
Data publikacji:
2023
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
sonar micro-Doppler
automatic recognition
SVM
RBF kernel
linear kernel
polynomial kernel
Opis:
In this paper, we propose using a propeller modulation on the transmitted signal (called sonar micro-Doppler) and different support vector machine (SVM) kernels for automatic recognition of moving sonar targets. In general, the main challenge for researchers and craftsmen working in the field of sonar target recognition is the lack of access to a valid and comprehensive database. Therefore, using a comprehensive mathematical model to simulate the signal received from the target can respond to this challenge. The mathematical model used in this paper simulates the return signal of moving sonar targets well. The resulting signals have unique properties and are known as frequency signatures. However, to reduce the complexity of the model, the 128-point fast Fourier transform (FFT) is used. The selected SVM classification is the most popular machine learning algorithm with three main kernel functions: RBF kernel, linear kernel, and polynomial kernel tested. The accuracy of correctly recognizing targets for different signal-to-noise ratios (SNR) and different viewing angles was assessed. Accuracy detection of targets for different SNRs (−20, −15, −10, −5, 0, 5, 10, 15, 20) and different viewing angles (10, 20, 30, 40, 50, 60, 70, 80) is evaluated. For a more fair comparison, multilayer perceptron neural network with two back-propagation (MLP-BP) training methods and gray wolf optimization (MLP-GWO) algorithm were used. But unfortunately, considering the number of classes, its performance was not satisfactory. The results showed that the RBF kernel is more capable for high SNRs (SNR = 20, viewing angle = 10) with an accuracy of 98.528%.
Źródło:
Archives of Acoustics; 2023, 48, 1; 49-61
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An Efficient Edge Preserving Interpolation Method for Underwater Acoustic Image Resolution Enhancement
Autorzy:
Priyadharsini, R.
Sree Sharmila, T.
Powiązania:
https://bibliotekanauki.pl/articles/2141674.pdf
Data publikacji:
2022
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
acoustic images
edge preserving interpolation
resolution enhancement
sonar
underwater
Opis:
Underwater acoustic images are acquired using sonar instrument that uses sound propagation to navigate and map the sea floor. The sonar devices are effectively used to create images of large area of the seabed. However, the visual perception of the object in the acoustic image depends on refraction, which is a function of changes in the speed of sound in successive layers of water. And refraction depends mainly on temperature, slightly on salinity and hydrostatic pressure. The quality and resolution of sonar imaging of the bottom depends on many other factors such as pitch, yaw and heave of the side scan sonar, the presence of volume scatterers in the water body, the distance of the sonar from the bottom and orientation of the object. Generally, the objects in an acoustic image would be of small size compared to their normal size as the distance between the sonar and object is larger. To detect and recognize the objects in the images, the resolution should be enhanced. In this paper, we propose an efficient edge preserving interpolation method for underwater acoustic image resolution enhancement which preserves the edge sharpness. The method handles the diagonal pixels in the first pass, in turn fills the horizontal and vertical pixels in the second pass. The results obtained are compared with the state-of-the-art interpolation techniques and the performance measures such as Peak Signal to Noise Ratio (PSNR) and Structural Similarity Index Measurement (SSIM) shows an improved result.
Źródło:
Archives of Acoustics; 2022, 47, 2; 267-274
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Conditions for multiple acquisition of echoes from stationary targets in successive transmissions of active sonars
Autorzy:
Kilian, Lech
Schmidt, Aleksander
Rudnicki, Mariusz
Powiązania:
https://bibliotekanauki.pl/articles/24201958.pdf
Data publikacji:
2022
Wydawca:
Politechnika Poznańska. Instytut Mechaniki Stosowanej
Tematy:
echosounder
sonar
side scan sonar
multiple echo
beam geometry
scanning speed
echosonda
sonar boczny
echo wielokrotne
geometria belki
prędkość skanowania
Opis:
In echolocation, the highest possible number of contacts with a detected target is clearly decisive on the possibilities of echo processing to optimise the estimation of distinctive characteristics of the observed target. In hydrolocation, the slow propagation of acoustic waves in water reduces the number of contacts of echosounders and sonars with detected targets. The article considers model conditions for acquiring multiple contacts with stationary targets detected by various sounding methods - with echosounders, classic active sonars and side looking sonars. Appropriate formulas explicitly linking the possible number of echo signals from the target in a specific geometry of the survey performed at the assumed speed are presented. These formulas are intuitively clear and not very complicated, but their value lies in the ability to instantly combine the vessel speed with the sounding effects, and may be a clear argument for imposing a low sounding speed, which make it difficult to steer the vessel.
Źródło:
Vibrations in Physical Systems; 2022, 33, 3; art. no. 2022308
0860-6897
Pojawia się w:
Vibrations in Physical Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Effect of Emergence Angle on Acoustic Transmission in a Shallow Sea
Autorzy:
Lu, Yanyang
Yang, Kunde
Liu, Hong
Huang, Chunlong
Powiązania:
https://bibliotekanauki.pl/articles/177665.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
underwater acoustic
emergence angle
transmission loss
active sonar detection
Opis:
In this study, the effect of the emergence angle of a source array on acoustic transmission in a typical shallow sea is simulated and analyzed. The formula we derived for the received signal based on the Normal Mode indicates that the signal is determined by the beamform on the modes of all sources and the samplings of all modes at the receiving depth. Two characteristics of the optimal emergence angle (OEA) are obtained and explained utilizing the aforementioned derived formula. The observed distributions of transmission loss (TL) for different sources and receivers are consistent with the obtained characteristics. The results of this study are valuable for the development and design of active sonar detection.
Źródło:
Archives of Acoustics; 2020, 45, 1; 3-9
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Training RBF NN Using Sine-Cosine Algorithm for Sonar Target Classification
Autorzy:
Wang, Yixuan
Yuan, LiPing
Khishe, Mohammad
Moridi, Alaveh
Mohammadzade, Fallah
Powiązania:
https://bibliotekanauki.pl/articles/1953523.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
classifiers
radial basis function neural network
sine-cosine algorithm
sonar
Opis:
Radial basis function neural networks (RBF NNs) are one of the most useful tools in the classification of the sonar targets. Despite many abilities of RBF NNs, low accuracy in classification, entrapment in local minima, and slow convergence rate are disadvantages of these networks. In order to overcome these issues, the sine-cosine algorithm (SCA) has been used to train RBF NNs in this work. To evaluate the designed classifier, two benchmark underwater sonar classification problems were used. Also, an experimental underwater target classification was developed to practically evaluate the merits of the RBF-based classifier in dealing with high-dimensional real world problems. In order to have a comprehensive evaluation, the classifier is compared with the gradient descent (GD), gravitational search algorithm (GSA), genetic algorithm (GA), and Kalman filter (KF) algorithms in terms of entrapment in local minima, the accuracy of the classification, and the convergence rate. The results show that the proposed classifier provides a better performance than other compared classifiers as it classifies the sonar datasets 2.72% better than the best benchmark classifier, on average.
Źródło:
Archives of Acoustics; 2020, 45, 4; 753-764
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Volume estimation of lakes and reservoirs based on aquatic drone surveys: The case study of Tuscany, Italy
Autorzy:
Giambastiani, Yamuna
Giusti, Riccardo
Cecchi, Stefano
Palomba, Francesca
Manetti, Francesco
Romanelli, Stefano
Bottai, Lorenzo
Powiązania:
https://bibliotekanauki.pl/articles/292923.pdf
Data publikacji:
2020
Wydawca:
Instytut Technologiczno-Przyrodniczy
Tematy:
deeper sonar
lake
pond
reservoir
volume model
Opis:
Following flood events and cloudbursts alternating with long drought periods, interest grew in the reservoirs, lakes and water basins in the Tuscany region. In-depth studies are needed to understand the role of water bodies in territorial resilience to climate change. Water volume is the main information to be collected to quantify and monitor their capacity. In this study, a methodology was developed for the estimation of water volume, based on depth measurements taken by sensors with low detection time and costs that can quantify the resource on a regional scale. The depth measuring instrument was a portable sounder with 95 satellite positioning system (Deeper Smart Sonar PRO + (WI-FI + GPS). 204 water bodies were measured. The results indicate that depth is a fundamental parameter to be detected in the field, to obtain the volume with automatic and precise tools. The calculated volume correlates well with the real volume with an R2 = 0.94. Elaboration of the results led to a model being developed to estimate the volume, knowing only the lake surface area. The database created can be used to conduct future studies on the dynamics of water resources in relation to climate change. It will also be possible to make comparisons with data obtained from satellite and LiDAR (light detection and ranging) surveys.
Źródło:
Journal of Water and Land Development; 2020, 46; 84-96
1429-7426
2083-4535
Pojawia się w:
Journal of Water and Land Development
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
A bathymetric unmanned surface vessel for effective monitoring of underwater aggregate extraction from the perspective of engineering facilities protection
Zdalna batymetria jako efektywna metoda monitoringu eksploatacji kruszywa spod lustra wody w aspekcie bezpieczeństwa obiektów inżynierskich
Autorzy:
Madusiok, Dominik
Powiązania:
https://bibliotekanauki.pl/articles/219635.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
kopalnie odkrywkowe
dokładność eksploatacji
pogłębiarka
struktura dna wyrobiska eksploatacyjnego
batymetria
Smart-Sonar-Boat
open-pit mine
economic mining
dredging machine
bottom composition
bathymetry
Smart Sonar Boat
Opis:
The study aimed to apply the protection from damage to engineering facilities located near a planned underwater aggregate extraction. The analysis was conducted in compliance with mining regulations and expert opinions. The study also aimed to assess the precision and correctness of the extraction, due to economic aspects. To reach the goals, in-situ research of the mining area was conducted, with the help of an advanced bathymetric device, based on the USV methodology. The instrument – named by the author as Smart-Sonar-Boat – was especially designed for underwater surveys in open-pit aggregate mines. The study analyzed the “Dwory” open-pit mine, located in southern Poland in the city of Oświęcim. The bathymetric results obtained contributed to improving the observation of changes in the bottom during the extraction. The applied USV method allowed for conducting the reliable evaluation of the mining work.
Pierwszym celem artykułu była ochrona obiektów inżynierskich zlokalizowanych w bliskim sąsiedztwie planowanej eksploatacji kruszyw naturalnych spod lustra wody. Analiza przeprowadzona została w odniesieniu do obowiązujących regulacji prawnych oraz specjalistycznych ekspertyz geologiczno-inżynierskich. Drugim celem była ocena dokładności i poprawności eksploatacji w aspekcie racjonalnej gospodarki złożem. Do przeprowadzenia badań in-situ wyrobiska eksploatacyjnego zastosowano zdalnie sterowane urządzenie batymetryczne oparte na metodzie USV (unmanned surface vessel), co w wolnym tłumaczeniu oznacza bezzałogowy pojazd pływający. Instrument pomiarowy, autorsko nazwany „Smart-Sonar-Boat”, został zaprojektowany do monitoringu podwodnej eksploatacji kruszyw. Obiektem badań była Kopalnia Kruszywa „Dwory” w Oświęcimiu. Uzyskane w ten sposób wyniki batymetryczne wraz z ich analizą statystyczną, w odniesieniu do wcześniej wykonanych ekspertyz badawczych, przyczyniły się do poprawy bezpieczeństwa eksploatacji oraz umożliwiły ocenę dokładności wybierania złoża do spągu.
Źródło:
Archives of Mining Sciences; 2019, 64, 2; 375-384
0860-7001
Pojawia się w:
Archives of Mining Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Analysis of the accuracy of shoreline mapping in inland navigational charts (Inland ENC) using photogrammetric and sonar images
Autorzy:
Łubczonek, Jacek
Łącka, Małgorzata
Zaniewicz, Grzegorz
Powiązania:
https://bibliotekanauki.pl/articles/134946.pdf
Data publikacji:
2019
Wydawca:
Akademia Morska w Szczecinie. Wydawnictwo AMSz
Tematy:
photogrammetry
navigation chart
hydrography
side scan sonar
accuracy assessment
mapping
Opis:
Shoreline mapping is one of the key stages in navigational charting. In terms of navigation, the shoreline marks the boundary of a river, which is often equivalent to the navigable water area. In cartographic terms, it is an important topological element between different objects that are adjacent to it. Currently, topographic objects are often mapped using photogrammetric materials obtained from various altitudes – satellite, airborne or low, which is associated with the use of an airborne UAV. Depending on the type of materials, the shoreline can be obtained in vector form with differing situational accuracy and differing degree of detail. In addition to the standard methods of processing vector data, the research in this paper also included the use of sonar images, enabling the detection of the shoreline with the use of a surveying hydrographic unit. On the basis of the collected photogrammetric and sonar images of different spatial resolution, an analysis of the accuracy of shoreline mapping was performed in terms of the situational accuracy and the level of detail in its representation. The results of the research provided the basis for the determination of dedicated remote sensing materials enabling the development of maps for inland navigation.
Źródło:
Zeszyty Naukowe Akademii Morskiej w Szczecinie; 2019, 58 (130); 45-54
1733-8670
2392-0378
Pojawia się w:
Zeszyty Naukowe Akademii Morskiej w Szczecinie
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of the Azimuth Angle of the Arrival Direction for an Ultrasonic Signal by Using Indirect Determination of the Phase Shift
Autorzy:
Kreczmer, Bogdan
Powiązania:
https://bibliotekanauki.pl/articles/177127.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
ultrasonic range finder
sonar
direction of arrival
Opis:
The paper presents and discusses a method of azimuth determination of ultrasonic echo arrival in air. The basis of the presented approach is the assumption that the received signal is a narrowband one. In this way, the direction of the signal arrival can be determined based on its phase shift using two receivers. When the distance between the receivers exceeds half of the wavelength of the received signal, a problem of ambiguity in determining the angle of arrival arises. To solve this, a method using multiple pairs of receivers was used. Its robustness and temperature dependence is analysed. The most import ant advantages of the presented approach are simplified computations and low hardware requirements. Experimental data made it possible to show that for strong echoes, the accuracy is higher than 0.5°. In the case of weak echos, it is reduced to about 2°. Because the method is based on phase shift measurement, the ultrasonic sonar that uses this method can be compact in size. Moreover, owing to the theoretical analysis, certain properties of the mutual location of the receivers were found and formally proved. They are crucial for determining proper receivers’ inter-distances.
Źródło:
Archives of Acoustics; 2019, 44, 3; 585-601
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Multi-Layer Perceptron Neural Network Utilizing Adaptive Best-Mass Gravitational Search Algorithm to Classify Sonar Dataset
Autorzy:
Mosavi, Mohammad Reza
Khishe, Mohammad
Naseri, Mohammad Jafar
Parvizi, Gholam Reza
Ayat, Mehdi
Powiązania:
https://bibliotekanauki.pl/articles/176971.pdf
Data publikacji:
2019
Wydawca:
Polska Akademia Nauk. Czasopisma i Monografie PAN
Tematy:
MLP NN
Multi-Layer Perceptron Neural Network
ABGSA
Adaptive Best Mass Gravitational Search Algorithm
sonar
classification
Opis:
In this paper, a new Multi-Layer Perceptron Neural Network (MLP NN) classifier is proposed for classifying sonar targets and non-targets from the acoustic backscattered signals. Besides the capabilities of MLP NNs, it uses Back Propagation (BP) and Gradient Descent (GD) for training; therefore, MLP NNs face with not only impertinent classification accuracy but also getting stuck in local minima as well as lowconvergence speed. To lift defections, this study uses Adaptive Best Mass Gravitational Search Algorithm (ABGSA) to train MLP NN. This algorithm develops marginal disadvantage of the GSA using the bestcollected masses within iterations and expediting exploitation phase. To test the proposed classifier, this algorithm along with the GSA, GD, GA, PSO and compound method (PSOGSA) via three datasets in various dimensions will be assessed. Assessed metrics include convergence speed, fail probability in local minimum and classification accuracy. Finally, as a practical application assumed network classifies sonar dataset. This dataset consists of the backscattered echoes from six different objects: four targets and two non-targets. Results indicate that the new classifier proposes better output in terms of aforementioned criteria than whole proposed benchmarks.
Źródło:
Archives of Acoustics; 2019, 44, 1; 137-151
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
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:
Identification of sonar detection signal based on fractional Fourier transform
Autorzy:
Wang, B.
Tang, J.
Yu, F.
Zhu, Z.
Powiązania:
https://bibliotekanauki.pl/articles/259724.pdf
Data publikacji:
2018
Wydawca:
Politechnika Gdańska. Wydział Inżynierii Mechanicznej i Okrętownictwa
Tematy:
fractional Fourier transform
watermark
sonar
Opis:
Aiming at the source of underwater acoustic emission, in order to identify the enemy emission sonar source accurately. Using the digital watermarking technology and combining with the good time-frequency characteristics of fractional Fourier transform (FRFT),this paper proposes a sonar watermarking method based on fractional Fourier transform. The digital watermark embedding in the fractional Fourier transform domain and combined with the coefficient properties of the sonar signal in the fractional Fourier transform to select the appropriate watermark position. Using the different characteristics of the signals before and after embedding, an adaptive threshold was set for the watermark detection to realize the discrimination of sonar signals. The simulation results show the feasibility and has better resolution and large watermark capacity of this method, while the robustness of the watermark is better, and the detection precision is further improved.
Źródło:
Polish Maritime Research; 2018, S 2; 125-131
1233-2585
Pojawia się w:
Polish Maritime Research
Dostawca treści:
Biblioteka Nauki
Artykuł
Wyświetlanie 1-15 z 97

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