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Search results for: RADIO WAVE PROPAGATION
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Changes in conditions of acoustic wave propagation in the Gdansk deep as an effect of climate changes in the Baltic Sea region
PublicationThe article presents the results from a research project investigating acoustic climate changes in the Gdansk Deep based on data extending from 1902 to 2019. This part of the southern Gotland Basin, is rarely discussed in the scientific literature. The speed of sound in the seawater is a function of temperature, salinity, and depth. In such shallow sea as Baltic Sea, the impact of depth is not substantial. The other two factors...
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Wave propagation signals in concrete beams under 3-point bending
Open Research DataThe DataSet contains the results of the mechanical behaviour of a concrete beams with dimensions 40 x 40 x 160 cm3under the 3-point bending. The beams were made of concrete with the following ingredients: CEM I 42.5R (450 kg/m3), water (177 kg/m3), sand 0-2 (675 kg/m3) and gravel 2-8 (675 kg/m3). The bending test was performed using a Zwick/Roell Z10...
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Propagacja fali wzdłużnej w pręcie z pęknieciem poprzecznym. Longitudinal wave propagation in a rod with a transverse crack.
PublicationW pracy przedstawiono wyniki analizy propagacji fali wzdłuznej w pręcie z pęknięciem poprzecznym.
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Modelling of in-plane wave propagation in a plate using spectral element method and Kane-Mindlin theory with application to damage detection
PublicationThis paper presents results of experimental and numerical analyses of in-plane waves propagatingin a 5 mm-thick steel plate in the frequency range of 120-300 kHz. For such a thickness/frequency ratio,extensional waves reveal dispersive character. To model in-plane wave propagation taking into account thethickness-stretch effect, a novel 2D spectral element, based on the Kane-Mindlin theory, was formulated. Anapplication of in-plane...
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Damage imaging algorithm for non-destructive inspection of CFRP/steel adhesive joints based on ultrasonic guided wave propagation
PublicationThe paper concerns assessing the quality of the adhesive connection between a steel plate and the reinforcing CFRP laminate. A three-stage algorithm for non-destructive damage imaging was developed. As the first step, an initial study involving dispersion curves of joint components was executed to determine the material parameters and the appropriate excitation frequency. During the second step, damage identification in three-layer...
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Modelling of in-plane wave propagation in a plate using spectral element method and Kane–Mindlin theory with application to damage detection
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Investigations on the influence CuO doping on elastic properties of Li2SO4–MgO–P2O5 glass system by means of acoustic wave propagation
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Influence of NiO doping on elastic properties of Li2SO4-MgO-P2O5 glass system-Investigation by means of acoustic wave propagation
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The spectral finite element model for analysis of flexural-shear coupled wave propagation. Part 2: Delaminated multilayer composite beam
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The spectral finite element model for analysis of flexural-shear coupled wave propagation. Part 2, Delaminated multilayer composite beam
PublicationW pracy przedstawiono, wykorzystując metodę elementów spektralnych, analizę wpływu delaminacji na propagację fali giętno-ścinającej w belce kompozytowej.
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The spectral finite element model for analysis of flexural-shear coupled wave propagation. Part 1, Laminated multilayer composite beam
PublicationW pracy przedstawiono model spectralnego elementu skończonego umożliwiającego symulację propagacji fali giętno-ścinającej w materiałąch kompozytowych.
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Measurements of guided wave propagation in CFRP/steel adhesive joints obtained by scanning laser vibrometry
Open Research DataThe DataSet contains guided wave signals measured in adhesive joints of steel plates (steel of type S355 with a thickness of 11.9 mm ) and carbon fibre reinforced polymer (CarboDur S1012 with a thickness of 1.24 mm). The samples were as follows: #0 – intact; #1 – 10% disbond; #2 – 20% disbond; #3 – 50% disbond; #4 – 80% disbond; #5 – 100% disbond.
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Elastic wave propagation signals in concrete cube (experimental and calculated using discrete element method)
Open Research DataThe DataSet contains the results of the elastic wave propagation. Both experimental and numerical signals were obtained for the concrete cube with dimensions of 50 × 50 × 50 mm3. The specimen was made of concrete with called mortar concrete. The ingredients of the concrete mix were as follows: CEM I 42.5R (500 kg/m3), sand 0 – 2 (1500 kg/m3) and water...
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Damage detection in 3D printed plates using ultrasonic wave propagation supported with weighted root mean square calculation and wavefield curvature imaging
Publication3D printing (additive manufacturing, AM) is a promising approach to producing light and strong structures with many successful applications, e.g., in dentistry and orthopaedics. Many types of filaments differing in mechanical properties can be used to produce 3D printed structures, including polymers, metals or ceramics. Due to the simplicity of the manufacturing process, biodegradable polymers are widely used, e.g., polylactide (polylactide...
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Ultrasonic wave propagation and digital image correlation measurements of steel bars under 3-point bending
Open Research DataThe DataSet contains the results of the mechanical behaviour of a bar under a 3-point bending test. The bar was made of steel and had a cross-section of 5.96 × 5.96 mm2 and a length of 200 mm. The three-point bending test was performed using a Zwick/Roell Z10 universal testing machine (UTM), with a distance between supports of 12 cm. The parameters...
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Ultrasonic wave propagation, digital image correlation and X-ray micro-computed tomography measurements of concrete during splitting (cube #3)
Open Research DataThe DataSet contains the results of the mechanical behaviour of a concrete cube under the splitting test. The cube had dimensions 70 x 70 x 70 cm3 and was made of concrete with the following ingredients: cement type CEM I 42.5R (330 kg/m3), water (165 kg/m3), aggregate 0/2 mm (710 kg/m3), aggregate 2/8 mm (664 kg/m3), aggregate 8/16 mm (500 kg/m3),...
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Ultrasonic wave propagation, digital image correlation and X-ray micro-computed tomography measurements of concrete during splitting (cube #1)
Open Research DataThe DataSet contains the results of the mechanical behaviour of a concrete cube under the splitting test. The cube had dimensions 70 x 70 x 70 cm3 and was made of concrete with the following ingredients: cement type CEM I 42.5R (330 kg/m3), water (165 kg/m3), aggregate 0/2 mm (710 kg/m3), aggregate 2/8 mm (664 kg/m3), aggregate 8/16 mm (500 kg/m3),...
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Ultrasonic wave propagation, digital image correlation and X-ray micro-computed tomography measurements of concrete during splitting (cube #4)
Open Research DataThe DataSet contains the results of the mechanical behaviour of a concrete cube under the splitting test. The cube had dimensions 70 x 70 x 70 cm3 and was made of concrete with the following ingredients: cement type CEM I 42.5R (330 kg/m3), water (165 kg/m3), aggregate 0/2 mm (710 kg/m3), aggregate 2/8 mm (664 kg/m3), aggregate 8/16 mm (500 kg/m3),...
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Ultrasonic wave propagation, digital image correlation and X-ray micro-computed tomography measurements of concrete during splitting (cube #2)
Open Research DataThe DataSet contains the results of the mechanical behaviour of a concrete cube under the splitting test. The cube had dimensions 70 x 70 x 70 cm3 and was made of concrete with the following ingredients: cement type CEM I 42.5R (330 kg/m3), water (165 kg/m3), aggregate 0/2 mm (710 kg/m3), aggregate 2/8 mm (664 kg/m3), aggregate 8/16 mm (500 kg/m3),...
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Measurements of ultrasonic bulk and guided wave propagation in additively manufactured cubes and plates obtained by ultrasonic pulse velocity analyzer and scanning laser vibrometry
Open Research DataThe DataSet contains the results of measurements of ultrasonic wave propagation in additively manufactured samples made of polylactic acid (PLA). Three types of raster angles in two consecutive layers were assumed: 0°/90° (#1), 45°/-45° (#2) and 90°/90° (#3) with respect to the x-axis. For each printing variants a cubic sample (#C1-3) with dimensions...
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Ultrasonic wave propagation and digital image correlation measurements of polyolefin fibre-reinforced concrete beams under 3-point bending (beam B-002)
Open Research DataThe DataSet contains the results of the mechanical behaviour of a concrete beam under a 3-point bending test. The beams had dimensions 15 x 15 x 70 cm3. The beam B-Con was made of concrete without fibres (as the reference beam), while beams B-002, B-004, and B-006 were manufactured from the concrete mix containing 2 kg/m3, 4 kg/m3 and 6 kg/m3 of fibres,...
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Ultrasonic wave propagation and digital image correlation measurements of polyolefin fibre-reinforced concrete beams under 3-point bending (beam B-Con)
Open Research DataThe DataSet contains the results of the mechanical behaviour of a concrete beam under a 3-point bending test. The beams had dimensions 15 x 15 x 70 cm3. The beam B-Con was made of concrete without fibres (as the reference beam), while beams B-002, B-004, and B-006 were manufactured from the concrete mix containing 2 kg/m3, 4 kg/m3 and 6 kg/m3 of fibres,...
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Ultrasonic wave propagation and digital image correlation measurements of polyolefin fibre-reinforced concrete beams under 3-point bending (beam B-004)
Open Research DataThe DataSet contains the results of the mechanical behaviour of a concrete beam under a 3-point bending test. The beams had dimensions 15 x 15 x 70 cm3. The beam B-Con was made of concrete without fibres (as the reference beam), while beams B-002, B-004, and B-006 were manufactured from the concrete mix containing 2 kg/m3, 4 kg/m3 and 6 kg/m3 of fibres,...
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Ultrasonic wave propagation and digital image correlation measurements of polyolefin fibre-reinforced concrete beams under 3-point bending (beam B-006)
Open Research DataThe DataSet contains the results of the mechanical behaviour of a concrete beam under a 3-point bending test. The beams had dimensions 15 x 15 x 70 cm3. The beam B-Con was made of concrete without fibres (as the reference beam), while beams B-002, B-004, and B-006 were manufactured from the concrete mix containing 2 kg/m3, 4 kg/m3 and 6 kg/m3 of fibres,...
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Jacek Stefański prof. dr hab. inż.
PeopleJJacek Stefański received M.Sc., Ph.D. and D.Sc. degrees in telecommunications engineering from Gdansk University of Technology (GUT), Poland, in 1993, 2000 and 2012, respectively. Awarded title of Professor by the President of Poland in 2020. Currently, he works as a professor at the Department of Radio Communication Systems and Networks (DRCSN) in GUT. From 2005 to 2009, he worked as an assistant professor in the National Institute...
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Sławomir Jerzy Ambroziak dr hab. inż.
PeopleSławomir J. Ambroziak was born in Poland, in 1982. He received the M.Sc., Ph.D. and D.Sc. degrees in radio communication from Gdańsk University of Technology (Gdańsk Tech), Poland, in 2008, 2013, and 2020 respectively. Since 2008 he is with the Department of Radiocommunication Systems and Networks of the Gdańsk Tech: 2008-2013 as Research Assistant, 2013-2020 as Assistant Professor, and since 2020 as Associate Professor. He is...
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An Empirical Propagation Model for Corridors in Office Buildings
PublicationThis paper presents an empirical propagation path loss model for corridors in office buildings. The proposed model estimates changeable character of radio signal attenuation, based on a special approach as a combination of the simple free-space model with the author’s model. The measurement stand and measurement scenario are described. The propagation path loss research have been made in corridor for different frequencies in range...
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New Indoor Positioning Algorithm for Distance Measurements
PublicationIn the paper a new indoor positioning algorithm is presented. This algorithm takes into account selected features of radio wave propagation in indoor environment. This results in improvement in accuracy of calculated position estimates. A comparative analysis of this new algorithm with Chan and Foy algorithms was made and described in the paper. This comparative analysis was made with utilization of real radio distance measurements.
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Do Leonardo da Vinci’s drawings, room acoustics and radio astronomy have anything in common?
PublicationAfter introducing Leonardo da Vinci’s (LdV) predecessors in the field of light propagation research, his drawings on the topic of reflecting light by a spherical mirror are analysed. The discovery of LdV is presented, according to which, at an infinitely distant source of rays, a small fragment of the canopy is enough to generate a focus, while the rest of the mirror forms a caustic for which LdV did not indicate an application....
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Nowy wewnątrzbudynkowy algorytm wyznaczania położenia obiektów
PublicationW referacie zaprezentowano nowy wewnątrzbudynkowy algorytm wyznaczania położenia obiektów WAP. W algorytmie tym uwzględnia się właściwości środowiska propagacyjnego, dzięki czemu dokładność estymat położenia obiektów wyznaczonych algorytmem WAP jest większa niż wyznaczonych znanymi algorytmami Chana oraz Foy’a. W referacie przedstawiono wyniki analizy porównawczej tych trzech algorytmów z użyciem rzeczywistych pomiarów odległości...
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Piotr Rajchowski dr inż.
PeoplePiotr Rajchowski (Member, IEEE) was born in Poland, in 1989. He received the E.Eng., M.Sc., and Ph.D. degrees in radio communication from the Gdańsk University of Technology (Gdańsk Tech), Poland, in 2012, 2013, and 2017, respectively. Since 2013, he has been working at the Department of Radiocommunication Systems and Networks, Faculty of Electronics, Telecommunications and Informatics, Gdańsk University of Technology, as a IT...
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Reliable testbed for indoor positioning systems
PublicationThis paper proposes a test environment for indoor localization system, based on radio wave propagation prosperities. The following sections presents variety of problems from the assessment of the existing localization system to the analysis of inconveniences which occur when comparison of different localization systems is implemented. The problem is associated with different testing environments presented in published papers is...
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Badania i analiza uwarunkowań propagacyjnych w środowisku uprzemysłowionym
PublicationGłówne osiągnięcia rozprawy: - wykonanie – zgodnie z wymaganiami normatywnymi zawartymi w zaleceniach ITU-R – nowatorskich badań tłumienia sygnału radiowego na terenie Głębokowodnego Terminalu Kontenerowego (ang. Deepwater Container Terminal - DCT) w Gdańsku i zebranie obszernego materiału pomiarowego, liczącego blisko 290 tysięcy przypadków propagacyjnych, - przeprowadzenie statystycznych badań przydatności wybranych znanych modeli...
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Jarosław Górski prof. dr hab. inż.
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Characteristics of Propagation Conditions in the Container Terminal Environment
PublicationIn the paper a characteristics of propagation conditions in the container terminal environment is presented. The investigated environment is characterized on the example of Gdansk Deepwater Container Terminal in Poland. An empirical propagation model for path loss calculation in mobile radio links in a container terminal environment is presented.
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[ITiT] Transmission Channel in Radio Communication Systems
e-Learning Courses{mlang pl} Dyscyplina: informatyka techniczna i telekomunikacja Zajęcia fakultatywne dla doktorantów II roku Prowadzący: dr hab. inż. Sławomir Ambroziak, prof. PG Liczba godzin: 15 Forma zajęć: wykład {mlang} {mlang en} Discipline: technical informatics and telecommunications Elective course for 2nd-year PhD students Academic teachers: dr hab. inż. Sławomir Ambroziak, prof. PG Total hours of training: 15 teaching hours Course...
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The propagation of the waves in the CTO S.A. towing tank
PublicationThe paper presents the results of research focused on the wave propagation in the CTO S.A. deepwater towing tank. In the scope of paper, the wavemaker transfer function was determined for regular waves, based on the Biésel Transfer Function and further for irregular waves, based on Hasselman model of nonlinear energy transfer. The phenomena: wave damping, wave breakdown and wave reflection, were measured, analyzed and mathematically...
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[ITiT] Transmission Channel in Radio Communication Systems - 2023/2024
e-Learning Courses{mlang pl} Dyscyplina: informatyka techniczna i telekomunikacja Zajęcia fakultatywne dla doktorantów II roku Prowadzący: dr hab. inż. Sławomir Ambroziak, prof. PG Liczba godzin: 15 Forma zajęć: wykład {mlang} {mlang en} Discipline: technical informatics and telecommunications Elective course for 2nd-year PhD students Academic teachers: dr hab. inż. Sławomir Ambroziak, prof. PG Total hours of training: 15 teaching hours Course...
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Data obtained by computation for X-ray focusing using oriented Gaussian beams
Open Research DataThe propagation of X-ray waves through an optical system consisting of several X-ray refractive lenses is considered. Gaussian beams are exact solutions of the paraxial equation. The Helmholtz equation describes the propagation of a monochromatic electromagnetic wave. Since the widths of the beams are much larger than the wavelength of X-rays, Gaussian...
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Person Tracking in a Ferry Environment Using Ultra-Wide Band Radio Interface
PublicationThis article presents research and analysis of effectiveness of tracking moving people in an environment of passenger ferry, using measurements of propagation time of ultra-wide band radio signal (UWB - Ultra-Wide Band). Constructed measurement stand and results of measurements carried out in a real propagation conditions were shortly discussed.
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Generation and Propagation of Nonlinear Waves in a Towing Tank
PublicationThe paper presents the results of the research focused on linear and nonlinear wave generation and propagation in a deepwater towing tank equipped with a single flap-type wavemaker of variable draft. The problem of wave generation and propagation has been theoretically formulated and solved by applying an analytical method; linear and nonlinear solutions were obtained. The linear solution has been verified experimentally. The...
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Waves Along Fractal Coastlines: From Fractal Arithmetic to Wave Equations
PublicationBeginning with addition and multiplication intrinsic to a Koch-type curve, we formulate and solve wave equation describing wave propagation along a fractal coastline. As opposed to examples known from the literature, we do not replace the fractal by the continuum in which it is embedded. This seems to be the first example of a truly intrinsic description of wave propagation along a fractal curve. The theory is relativistically...
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Empirical Propagation Model for the Container Terminal Environment
PublicationIn the paper the empirical propagation model for mobile radio links in a container terminal environment is presented and the investigated environment Deepwater Container Terminal in Gdansk, Poland) is characterized. Described empirical model was elaborated on the basis of almost 290 thousand propagation path measurements in real conditions. The diversity of conditions occurring in different places of the container terminal has...
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Radio Link Measurement Methodology for Location Service Applications
PublicationThe aim of this paper is the methodology of measurements executed in a radio link for the realization of radiolocation services in radiocommunication networks, particularly in cellular networks. The main results of the measurements obtained in the physical layer of the universal mobile telecommunications system (UMTS) are introduced. A new method for the utilization of the multipath propagation phenomenon to improve the estimation...
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Selected Propagation Models Modification for Application in Container Terminal
PublicationIt is particularly important to look for any propagation model that could be useful for designing mobile radio systems in container terminal environment. The selected propagation models have been investigated. The applied research methodology has been described too. Results of the statistical adjustment in terms of signal loss determination in such environment have been analysed. The analysis have proved effectiveness of adjustment...
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Propagation of Acoustic Disturbances in Shallow Sea
PublicationPropagation of acoustic waves in shallow sea differs fundamentally from the same phenomenon occurring in deep sea in view of non-negligible distance from the sea bottom in the first case, where presence of two regions limiting the water layer results in the acoustic pressure distribution induced by a harmonic source has an interferential nature as a result of multi-path propagation of the acoustic signal. These interferential properties...
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Oriented Gaussian beams for high-accuracy computation with accuracy control of X-ray propagation through a multi-lens system
PublicationA highly accurate method for calculating X-ray propagation is developed. Within this approach, the propagating wave is represented as a superposition of oriented Gaussian beams. The direction of wave propagation in each Gaussian beam agrees with the local direction of propagation of the X-ray wavefront. When calculating the propagation of X-ray waves through lenses, the thin lens approximation is applied. In this approximation,...
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Estimation of transmission quality in cellular systems based on indicators measured by the radio module
PublicationThe article presents a measurement stand for testing transmission quality in cellular systems such as LTE, NB-IoT, UMTS and GSM. The results of BLER and throughput measurements for various propagation conditions as well as results of quality indicators appropriate for mentioned technologies measured by commercial radio module are presented. Those measurements were utilized to analyze the possibility of estimating the transmission...
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Empirical Adjustment of the Selected Propagation Models for Application in the Peculiar Environment of the Container Terminal
PublicationIt is important to look for any propagation model that could be useful for designing mobile radio systems in container terminal environment. Selected propagation models have been investigated. The applied research methodology has been described too. Results of the statistical adjustment in terms of signal loss determination in such environment have been analysed. The analysis has proved effectiveness of adjustment by increasing...
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Velocity measurement using the fdoa method in ground-based radio navigation system
PublicationVelocity is one of the main navigation parameters of the moving objects. However some systems of position estimation using radio wave measurements cannot provide velocity data due to limitation of their performance. In this paper a velocity measurement method for DS-CDMA radio navigation system is proposed, which doesn’t require full synchronization of reference stations carrier frequencies. The article presents basics of FDOA...