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Wyszukujesz frazę "Marszal, J." wg kryterium: Autor


Wyświetlanie 1-7 z 7
Tytuł:
Silent sonar with matched filtration
Autorzy:
Salamon, R.
Marszal, J.
Schmidt, J.
Rudnicki, M.
Powiązania:
https://bibliotekanauki.pl/articles/331754.pdf
Data publikacji:
2011
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
Radars with continuous wave frequency (CW FM sonars) are used in radiolocation as ‘silent radars’. They determine the distance to target by measuring the difference between the frequency of the sounding signal and echo signal. The article presents the principle of operation and parameters of silent CW FM sonars. Target distance determined by these sonars is based on the signal at the output of the matched filter. The Doppler effect is studied in detail to identify its effect on the sonar’s parameters. The results of theoretical calculations are presented together with the results of the sonar’s computer simulation.
Źródło:
Hydroacoustics; 2011, 14; 199-208
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Electronic stabilization of beams in sonar with cylindrical array
Autorzy:
Marszal, J.
Leśniak, W.
Salamon, R.
Schmidt, J.
Powiązania:
https://bibliotekanauki.pl/articles/332362.pdf
Data publikacji:
2006
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The article presents the principle of operation of the beamformer of sonar with a cylin-drical array. It demonstrates that a modified beamformer can be used for beam electronic stabilization. The paper presents the algorithm of a digital beamformer used to ensure that the beam’s axis is maintained in a horizontal plane when the ship’s pitch and roll are known. Finally, the article gives an overview of the technical problems of electronic beam deflection.
Źródło:
Hydroacoustics; 2006, 9; 119-124
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Method for improving multibeam sonar bearing accuracy
Autorzy:
Leśniak, W.
Marszal, J.
Salamon, R.
Zachariasz, K.
Schmidt, J.
Powiązania:
https://bibliotekanauki.pl/articles/332790.pdf
Data publikacji:
2009
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
multibeam sonar
sonar bearing accuracy
sonars
Opis:
The paper presents a simple method for improving multibeam sonar bearing accuracy. The principle proposed here is similar to the monopulse method, a solution commonly used in radars and sonars. With no manual or automatic beam rotation, the method offers a substantial reduction in the demand for sonar computational effort. It significantly reduces bearing error for a relatively high signal to noise ratio. The paper gives a boundary value of the output signal to noise ratio which when exceeded satisfactorily improves bearing accuracy.
Źródło:
Hydroacoustics; 2009, 12; 98-108
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Impact of Microphytobenthos Photosynthesis on the Characteristics of the Echo Signal from Baltic Sandy Sediments
Autorzy:
Gorska, N.
Kowalska-Duda, E.
Marszal, J.
Schmidt, J.
Klusek, Z.
Powiązania:
https://bibliotekanauki.pl/articles/177331.pdf
Data publikacji:
2015
Wydawca:
Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:
hydroacoustics
backscattering
microphytobenthos photosynthesis
Baltic Sea
Opis:
The understanding the influence of biological processes on the characteristics of the signals backscattered by the sea floor is crucial in the development of the hydroacoustical benthic habitat classification techniques. The impact of the microphytobenthos photosynthesis on the acoustical backscattering properties of the Atlantic sandy sediments was previously demonstrated by Holliday et al. (2004) and Wildman and Huettel (2012). To account for the sensitivity of the hydroacoustical classification techniques to the backscattering properties of local marine sediments, it is important to understand the microphytobenthos photosynthesis impact for the Baltic Sea where the techniques are being actively developed now. This is the main motivation of the paper. In the paper the influence of the microphytobenthos photosynthesis on the characteristics of the echo signals reflected by sandy sediments in the typical Baltic temperature and the salinity conditions is discussed. The interdisciplinary multiday laboratory experiment was conducted to study the impact of benthic microalgal photosynthesis on the characteristics of the echo signal reflected by sandy sediments. Hydroacoustical data were collected under controlled constant light, temperature and salinity conditions. The oxygen content at different levels of the water column was simultaneously monitored.
Źródło:
Archives of Acoustics; 2015, 40, 3; 395-405
0137-5075
Pojawia się w:
Archives of Acoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Time variable gain for long range sonar with chirp sounding signal
Autorzy:
Marszal, J.
Ostrowski, Z.
Schmidt, J.
Kilian, L.
Jedel, A.
Schmidt, A.
Powiązania:
https://bibliotekanauki.pl/articles/332524.pdf
Data publikacji:
2007
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The main purpose of applying Time Variable Gain (TVG) in active sonars with digital signal processing is to reduce dynamic range of echo signal and adapt it to the dynamic range of the analogue to digital conversion. With high transmission losses level, the dynamic range of the input signal in long range sonars can be very high and even exceed 200 dB. When chirp sounding signals with matched filtration are used, sonars can reach very long ranges. The article presents optimisation of TVG control for long range sonars. It also looks at the influence of chirp sounding signal compression, the result of digital matched filtration, for the TVG controlling. The examples of obtained results are presented.
Źródło:
Hydroacoustics; 2007, 10; 117-122
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
High accuracy hydroacoustic system to study codend model parameters
Autorzy:
Marszal, J.
Schmidt, J.
Jedel, A.
Schmidt, A.
Wojan, Z.
Zachariasz, K.
Leśniak, W.
Powiązania:
https://bibliotekanauki.pl/articles/331608.pdf
Data publikacji:
2008
Wydawca:
Polskie Towarzystwo Akustyczne
Tematy:
codend model
hydroacoustic system
fishing gear
Opis:
An important task of fishing gear designers is to develop effective selective fishing gears by optimizing its geometry. The high accuracy hydroacoustic system for codend geometry measurements was designed for developing the construction of cod codend for the Baltic fishery. The system consists of 10 pairs of hydrophones, measuring microprocessor device and notebook computer. The high frequency short pulse excitation combined with the matched digital filtering make it possible to obtain high resolution of measure data. Additionally the thermistors mounted in the hydrophones are used to calculate the local sound velocity and enable precision calibration of obtained measuring data. The construction solutions, the measuring procedure and examples of obtained data are presented below.
Źródło:
Hydroacoustics; 2008, 11; 271-278
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
Tytuł:
Modernization of ASW sonar SQS-56 at Gdansk University of Technology
Autorzy:
Marszal, J.
Schmidt, J.
Salamon, R.
Kilian, L.
Raganowicz, A.
Zachariasz, K.
Ostrowski, Z.
Jedel, A.
Rudnicki, M.
Sidorko, T.
Powiązania:
https://bibliotekanauki.pl/articles/331991.pdf
Data publikacji:
2010
Wydawca:
Polskie Towarzystwo Akustyczne
Opis:
The fast development of electronic technology and digital signal processing methods makes electronic devices, including sonar systems ones, obsolete very quickly. On the other hand the ships mechanical components including mechanical parts of sonars are operational for a few dozens of years. It makes good opportunity to modernize these devices by using modern electronic devices and new digital signal processing methods with application of existing antenna and mechanical systems. The paper presents the modernization of ASW sonar SQS-56 on the Polish frigate ORP “Kościusko”. The aim of modernization, the new parameters of the sonar and block diagram after modernization are presented.
Źródło:
Hydroacoustics; 2010, 13; 191-196
1642-1817
Pojawia się w:
Hydroacoustics
Dostawca treści:
Biblioteka Nauki
Artykuł
    Wyświetlanie 1-7 z 7

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