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Wyszukujesz frazę "Synthetic Aperture Radar" wg kryterium: Temat


Tytuł:
Synthetic Aperture Radar Using Emitters of Opportunity
Autorzy:
Serafin, P.
Kawalec, A.
Leśnik, C.
Pyć, M.
Pietrasiński, J.
Powiązania:
https://bibliotekanauki.pl/articles/226408.pdf
Data publikacji:
2012
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Synthetic Aperture Radar (SAR)
passive SAR
Opis:
The capability of a radar imaging system to stay undetected while gathering data is one of the most desired for military reconnaissance systems. This is particularly difficult to achieve for synthetic aperture radar (SAR), that have to emit electromagnetic energy all the time during the operation and to move along a strictly defined route. Therefore the idea of a passive imaging system although encountering many constraints seems to be very interesting. The possibilities of a passive synthetic aperture radar system working with different types of emitters of opportunity are described in the paper. Impact of signal characteristics on image quality and geometry issues are discussed among others. Results of computer simulations of such a system implementing different imaging algorithms as well as the results of the experiment performed with passive SAR system model are presented.
Źródło:
International Journal of Electronics and Telecommunications; 2012, 58, 4; 357-362
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Object georeferencing in UAV-based SAR terrain images
Autorzy:
Łabowski, M.
Kaniewski, P.
Serafin, P.
Wajszczyk, B.
Powiązania:
https://bibliotekanauki.pl/articles/320583.pdf
Data publikacji:
2016
Wydawca:
Polskie Forum Nawigacyjne
Tematy:
georeferencing
synthetic aperture radar
IMU
GNSS
Opis:
Synthetic aperture radars (SAR) allow to obtain high resolution terrain images comparable with the resolution of optical methods. Radar imaging is independent on the weather conditions and the daylight. The process of analysis of the SAR images consists primarily of identifying of interesting objects. The ability to determine their geographical coordi-nates can increase usability of the solution from a user point of view. The paper presents a georeferencing method of the radar terrain images. The presented images were obtained from the SAR system installed on board an Unmanned Aerial Vehicle (UAV). The sys-tem was developed within a project under acronym WATSAR realized by the Military University of Technology and WB Electronics S.A. The source of the navigation data was an INS/GNSS system integrated by the Kalman filter with a feed-backward correc-tion loop. The paper presents the terrain images obtained during flight tests and results of selected objects georeferencing with an assessment of the accuracy of the method.
Lotnicze zobrazowania terenu realizowane za pomocą radaru z syntetyczną aperturą pozwalają na uzyskanie wysokiej rozróżnialności porównywalnej z rozróżnialnością metod optycznych, mając jednocześnie nad nimi przewagę w postaci niezależności obserwacji od warunków pogodowych czy pory dnia. Proces analizy tak uzyskanych zobrazowań składa się przede wszystkim z identyfikacji interesujących obiektów. Możliwość określenia ich współrzędnych geograficznych pozwala na znaczące zwiększenie użyteczności tego rozwiązania z punktu widzenia potencjalnego użytkownika. W artykule przedstawiono metodę georeferencji zobrazowań terenu otrzymywanych za pomocą radaru z syntetyczną aperturą, który zainstalowano na pokładzie bezzałogowego statku powietrznego. System taki opracowano w ramach projektu WATSAR, zrealizowanego przez Wojskową Akademię Techniczną i WB Electronics S.A. Źródłem danych nawigacyjnych był system INS/GNSS, zintegrowany metodą filtracji pośredniej, z korekcją wstecz. W artykule zamieszczono radarowe zobrazowania terenu uzyskane podczas badań poligonowych systemu oraz wyniki georeferencji wybranych obiektów wraz z oceną dokładności wyznaczanego położenia.
Źródło:
Annual of Navigation; 2016, 23; 39-52
1640-8632
Pojawia się w:
Annual of Navigation
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Application for Displaying Synthetic Aperture Radar Imagery in Real-time Implementation and Results
Autorzy:
Borowiec, K.
Powiązania:
https://bibliotekanauki.pl/articles/226659.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Synthetic Aperture Radar (SAR)
real-time imaging
Opis:
The paper presents implementation and results of the application for displaying SAR (Synthetic Aperture Radar) imagery operating in real-time. The application performs SAR imagery formation and displays results in real-time after receiving of preprocessed data via an SAR processing application. The application was used in SARape (Synthetic Aperture Radar for all weather penetrating UAV application) project founded by the European Defence Agency. The real-time operation is achieved thanks to implementation based on multithreading.
Źródło:
International Journal of Electronics and Telecommunications; 2015, 61, 4; 345-350
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Cascade Feed Forward Neural Network-based Model for Air Pollutants Evaluation of Single Monitoring Stations in Urban Areas
Autorzy:
Capizzi, G.
Lo Sciuto, G.
Monforte, P.
Napoli, C.
Powiązania:
https://bibliotekanauki.pl/articles/226736.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
neural networks
Synthetic Aperture Radar (SAR)
mahalanobis distance
Opis:
In this paper, air pollutants concentrations for NO2, NO, NOx and PM10 in a single monitoring station are predicted using the data coming from other different monitoring stations located nearby. A cascade feed forward neural network based modeling is proposed. The main aim is to provide a methodology leading to the introduction of virtual monitoring station points consistent with the actual stations located in the city of Catania in Italy.
Źródło:
International Journal of Electronics and Telecommunications; 2015, 61, 4; 327-332
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Spatially Diverse ISAR Imaging for Classification Performance Enhancement
Autorzy:
Brisken, S.
Matthes, D.
Mathy, T.
Worms, J. G.
Powiązania:
https://bibliotekanauki.pl/articles/226557.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
inverse synthetic aperture radar
multistatic radar
non-cooperative target identification
Opis:
One popular approach to the problem of Non-Cooperative Target Identification is the use of 2D Inverse SAR images. Methods to successfully identify a target include the comparison of a set of scattering centers in the ISAR image to a database or the estimation of target dimensions. While working well in theory, these techniques face major difficulties in practice. In the conventional case of a monostatic radar, visibility of scattering centers varies with the target aspect angle due to fading. In this paper we examine that the visibility of scattering centers can be improved by incoherent addition of images from spatially distributed radars. The main focus lies in the description and results of a multistatic ISAR experiment carried out at Fraunhofer FHR. We display theoretically derived bistatic synchronization errors in a practical system and formulate additional multistatic synchronization requirements, necessary to add up the images.
Źródło:
International Journal of Electronics and Telecommunications; 2011, 57, 1; 15-22
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Generalized radar/radiometry imaging problems
Autorzy:
Prudyus, I.
Voloshynovskiy, S.
Synyavskyy, A.
Holotyak, T.
Lazko, L.
Powiązania:
https://bibliotekanauki.pl/articles/309072.pdf
Data publikacji:
2001
Wydawca:
Instytut Łączności - Państwowy Instytut Badawczy
Tematy:
radiometry systems
Synthetic Aperture Radar (SAR)
spatio-temporal imaging
Opis:
In the paper the results of spatio-temporal imaging simulation based on radar, synthetic aperture radar (SAR) and radiometry systems are presented. The analytical relationship between object scattering/emitting and the formed image is given and the general approach for the description of imaging system by means of Frendholm equation solution is developed. The potential limit of image resolution based on Rao-Cramer inequality is estimated.
Źródło:
Journal of Telecommunications and Information Technology; 2001, 4; 15-20
1509-4553
1899-8852
Pojawia się w:
Journal of Telecommunications and Information Technology
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radar Signatures of Complex Buried Objects in Ground Penetrating Radar
Autorzy:
Panzner, B.
Jöstingmeier, A.
Omar, A.
Powiązania:
https://bibliotekanauki.pl/articles/226559.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
image reconstruction
inverse scattering
Synthetic Aperture Radar (SAR)
GPR
migration
Opis:
The evaluation of radar signatures of buried objects for three experimental ground penetrating radar setups will be addressed in this paper. The contribution will present corresponding results and experiences. The performance of the imaging capabilities of the designed radar system will be assessed by reconstruction of complex shaped test objects, which have been placed within the ground. The influence of system parameters of the ground penetrating radar have been varied systematically in order to analyze their effects on the image quality. Among the modified parameters are the step size in transverse plane, height of the antenna over ground, frequency range, frequency points, antennas and varying instrument settings. A signal processing technique based on synthetic aperture radar has been applied on the measured raw data. The focus radius around a specific target has been analyzed concerning the compromise between image quality and processing time. The experiments demonstrate that the designed ground penetrating radar systems are capable for detection of buried objects with high resolution.
Źródło:
International Journal of Electronics and Telecommunications; 2011, 57, 1; 9-14
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Mapping of Surface Deformation and Displacement Associated with the 6.5 Magnitude Botswana Earthquake of 3 April 2017 Using DInSAR Analysis
Autorzy:
Thomas, Abraham
Powiązania:
https://bibliotekanauki.pl/articles/1837989.pdf
Data publikacji:
2020
Wydawca:
Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
Tematy:
differential interferometric synthetic aperture radar (DInSAR)
interferometry
Sentinel-1
Botswana earthquake
Opis:
The DInSAR analysis was performed for mapping surface deformation and displacement associated with the 6.5 magnitude Botswana earthquake of 3 April 2017 using Sentinel 1 data and SNAP. The analyses involved: coregistration of SAR images, interferogram formation, debursting, merging of sub swaths, topographic phase removal, phase filtering, phase unwrapping, orthorectification and calculation of vertical displacement for two situations (unmasked and masked with a layer of coherence ≥0.6). The vertical displacement for the unmasked situation ranged from −122 mm to +136 mm whereas in the masked layer it ranged from −84 mm to +122 mm. Negative surface deformation (subsidence) is seen in the epicentre region and eastern, north eastern, northern areas of the image whereas major positive surface deformations (uplift) are seen in the south western, western and north western corner part. Comparison of displacements with geology revealed that major deformation occurred in the Karoo basalts and lesser surface deformation has occurred in the Lebung Group rocks of the northern, NE and SW region. The elongated shape of deformation near the epicentre and positive vertical displacement seen towards the SW of the epicentre and negative vertical displacement seen towards NE of the epicentre reveals that the region has undergone uplifting and subsidence on either side of the area close to the epicentre (similar to faulting in a NW or SE direction). The boundaries of the uplift and subsidence regions inferred as long lineaments were digitised as faults. Comparison of the deformation with existing seismotectonic map revealed the existence of some north westerly faults seen in the region.
Źródło:
Geomatics and Environmental Engineering; 2020, 14, 4; 81-100
1898-1135
Pojawia się w:
Geomatics and Environmental Engineering
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Radar and Optical Images Fusion Using Stripmap SAR Data with Multilook Processing
Autorzy:
Kulpa, K.
Malanowski, M.
Misiurewicz, J.
Samczynski, P.
Powiązania:
https://bibliotekanauki.pl/articles/226571.pdf
Data publikacji:
2011
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Synthetic Aperture Radar (SAR)
focused SAR
multilook
multilook colour mapping
data fusion
Opis:
The paper presents the real-life data results of SAR and optical images data fusion. The fusion has been carried out for SAR images obtained in stripmap SAR mode using multilook processing with different methods of final image creation. The aim of the fusion was to enhance the target recognition capabilities on the Earth surface for a simple single-channel SAR receiver.
Źródło:
International Journal of Electronics and Telecommunications; 2011, 57, 1; 37-42
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Optimizing the minimum cost flow algorithm for the phase unwrapping process in SAR radar
Autorzy:
Dudczyk, J.
Kawalec, A.
Powiązania:
https://bibliotekanauki.pl/articles/200190.pdf
Data publikacji:
2014
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
IFSAR
Interferometry Synthetic Aperture Radar
minimum cost flow
MCF
phase unwrapping
PhU
Opis:
The last three decades have been abundant in various solutions to the problem of Phase Unwrapping in a SAR radar. Basically, all the existing techniques of Phase Unwrapping are based on the assumption that it is possible to determine discrete ”derivatives” of the unwrapped phase. In this case a discrete derivative of the unwrapped phase means a phase difference (phase gradient) between the adjacent pixels if the absolute value of this difference is less than π. The unwrapped phase can be reconstructed from these discrete derivatives by adding a constant multiple of 2π. These methods differ in that the above hypothesis may be false in some image points. Therefore, discrete derivatives determining the unwrapped phase will be discontinuous, which means they will not form an irrotational vector field. Methods utilising branch-cuts unwrap the phase by summing up specific discrete partial derivatives of the unwrapped phase along a path. Such an approach enables internally cohesive results to be obtained. Possible summing paths are limited by branch-cuts, which must not be intersected. These branch-cuts connect local discontinuities of discrete partial derivatives. The authors of this paper performed parametrization of the Minimum Cost Flow algorithm by changing the parameter determining the size of a tile, into which the input image is divided, and changing the extent of overlapping of two adjacent tiles. It was the basis for determining the optimum (in terms of minimum Phase Unwrapping time) performance of the Minimum Cost Flow algorithm in the aspect of those parameters.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2014, 62, 3; 511-516
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An improved Otsu method for oil spill detection from SAR images
Autorzy:
Yu, F.
Sun, W.
Li, J.
Zhao, Y.
Zhang, Y.
Chen, G.
Powiązania:
https://bibliotekanauki.pl/articles/47553.pdf
Data publikacji:
2017
Wydawca:
Polska Akademia Nauk. Instytut Oceanologii PAN
Tematy:
remote sensing
oil spill
detection
Otsu's method
accident
marine transport
synthetic aperture radar
Opis:
In recent years, oil spill accidents have become increasingly frequent due to the development of marine transportation and massive oil exploitation. At present, satellite remote sensing is the principal method used to monitor oil spills. Extracting the locations and extent of oil spill spots accurately in remote sensing images reaps significant benefits in terms of risk assessment and clean-up work. Nowadays the method of edge detection combined with threshold segmenta- tion (EDCTS) to extract oil information is becoming increasingly popular. However, the current method has some limitations in terms of accurately extracting oil spills in synthetic aperture radar (SAR) images, where heterogeneous background noise exists. In this study, we propose an adaptive mechanism based on Otsu method, which applies region growing combined with both edge detection and threshold segmentation (RGEDOM) to extract oil spills. Remote sensing images from the Bohai Sea on June 11, 2011 and the Gulf of Dalian on July 17, 2010 are utilized to validate the accuracy of our algorithm and the reliability of extraction results. In addition, results according to EDCTS are used as a comparator to further explore validity. The comparison with results according to EDCTS using the same dataset demonstrates that the proposed self-adapting algorithm is more robust and boasts high-accuracy. The accuracy computing by the adaptive algorithm is significantly improved compared with EDCTS and threshold method.
Źródło:
Oceanologia; 2017, 59, 3
0078-3234
Pojawia się w:
Oceanologia
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Estimation of Flight Path Deviations for SAR Radar Installed on UAV
Autorzy:
Łabowski, M.
Kaniewski, P.
Konatowski, S.
Powiązania:
https://bibliotekanauki.pl/articles/221533.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Unmanned Aerial Vehicle
Synthetic Aperture Radar
inertial measurement unit
Global Navigation Satellite System
Opis:
The paper presents a method of calculation of position deviations from a theoretical, nominally rectilinear trajectory for a SAR imaging system installed on board of UAV. The UAV on-board system consists of a radar sensor, an antenna system, a SAR processor and a navigation system. The main task of the navigation part is to determine the vector of differences between the theoretical and the measured trajectories of UAV center of gravity. The paper includes chosen results of experiments obtained during ground and flight tests.
Źródło:
Metrology and Measurement Systems; 2016, 23, 3; 383-391
0860-8229
Pojawia się w:
Metrology and Measurement Systems
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
An analysis of Chosen Image Formation Algorithms for Synthetic Aperture Radar with FMCW
Autorzy:
Okoń-Fąfara, M.
Serafin, P.
Kawalec, A.
Powiązania:
https://bibliotekanauki.pl/articles/227061.pdf
Data publikacji:
2016
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
signal processing
synthetic aperture radar
time domain correlation
range-Doppler algorithm
range migration algorithm
Opis:
The modelling of FMCW SAR systems, due to long signal duration time, commonly used start-stop approximation for pulsed radars causes errors in the image. Continuous motion of the radar platform results in additional range-azimuth couplings and range walk term that should be considered in processing of signal from this type of radar. The paper presents an analysis of the following algorithms: Time Domain Correlation (TDC), Range Doppler Algorithm (RDA), and Range Migration Algorithm (RMA). The comparison of the algorithms is based on theoretical estimation of their computation complexity and the quality of images obtained on the basis of real signals of FMCW SAR systems.
Źródło:
International Journal of Electronics and Telecommunications; 2016, 62, 4; 323-328
2300-1933
Pojawia się w:
International Journal of Electronics and Telecommunications
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Azimuth ambiguity suppression in SAR images using Doppler-sensitive signals
Autorzy:
Leśnik, Cz.
Serafin, P.
Kawalec, A.
Powiązania:
https://bibliotekanauki.pl/articles/200612.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
Synthetic Aperture Radar (SAR)
SAR
azimuth ambiguity
Doppler-sensitive signals
dwuznaczność azymutu
sygnał Dopplera
Opis:
In the article the problem of the azimuth ambiguity in synthetic aperture radar (SAR) images and its genesis are presented. A method of suppressing the ambiguities by utilization of Doppler-sensitive signals is proposed, and the necessary modifications to the SAR synthesis algorithm are discussed. The SAR system parameters required for an optimal performance of the method are discussed and simulation results are presented.
Źródło:
Bulletin of the Polish Academy of Sciences. Technical Sciences; 2015, 63, 1; 221-227
0239-7528
Pojawia się w:
Bulletin of the Polish Academy of Sciences. Technical Sciences
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Monitoring of displacements and deformations of the earth’s surface near the Stebnyk city using radar images of Sentinel-1
Autorzy:
Trevoho, Ihor
Chetverikov, Borys
Babiy, Lubov
Malanchuk, Mariia
Powiązania:
https://bibliotekanauki.pl/articles/145388.pdf
Data publikacji:
2020
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
interferometria radarowa
radar
deformacja powierzchni
radar interferometry
Synthetic Aperture Radar
Sentinel-1
deformations of the Earth’s surface
Opis:
This article applies radar interferometry technologies implemented in the ENVI SARscape and SNAP software environment provided by the processing of data from the Sentinel-1 satellite. The study was carried out based on six radar images of Sentinel-1A and Sentinel -1B taken from September 2017 until February 2018 with an interval of one month and on the radar-module of the already mentioned SNAP software. The main input data for solving the considered problem are radar images received from the satellite Sentinel-1B on the territory of Stebnyk-Truskavets for six months with an interval of one month. Monitoring of the Earth’s surface using radar data of the Sentinel-1A with a synthesized aperture is implemented with the application of interferometric methods of Persistent Scatterers and Small baselines interferometry for estimating small displacements of the Earth’s surface and structures. The obtained quantitative and qualitative indicators of monitoring do not answer the processes that take place and lead to vertical displacements the six months but do provide an opportunity to assess the extent and trends of their development. The specification in each case can be accomplished by ground methods, which greatly simplify the search for sites with critical parameters of vertical displacements which can have negative consequences and lead to an emergency.
Źródło:
Geodesy and Cartography; 2020, 69, 1; 85-96
2080-6736
2300-2581
Pojawia się w:
Geodesy and Cartography
Dostawca treści:
Biblioteka Nauki
Artykuł

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