Autor: Schmidt, K. - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: Code signals transmission using MFSK modulation in shallow waters
Autorzy:: Zachariasz, K.
Schmidt, J.
Salamon, R.
Powiązania:: https://bibliotekanauki.pl/articles/332705.pdf
Data publikacji:: 2001
Wydawca:: Polskie Towarzystwo Akustyczne
Opis:: The paper presents an acoustic system for the transmission of digital data in shallow coastal waters of which multi-path propagation and intense reverberations are characteristic. To ensure a small error probability of moderate speed transmission, the system uses corrective codes and a technique of incoherent modulation MFSK (Mufti Frequency Shift Keying). To synthesise the transmission signal, estimate the spectrum of the signal received and code and decode the channels, a DSP processor was used. The paper includes the results of a computer simulation in which the system was put to work in the presence of Gaussian noise. The system was tested in shallow coastal waters and the results are discussed in the paper.
Źródło:: Hydroacoustics; 2001, 4; 261-264
1642-1817
Pojawia się w:: Hydroacoustics
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 2.

Tytuł:: Underwater communication system for shallow water using modified MFSK modulation
Autorzy:: Schmidt, J.
Zachariasz, K.
Salamon, R.
Powiązania:: https://bibliotekanauki.pl/articles/332663.pdf
Data publikacji:: 2005
Wydawca:: Polskie Towarzystwo Akustyczne
Opis:: The paper describes the design and operation of the Modified MFSK system for underwater communication. Its function is to transmit data and commands from ships to underwater objects in shallow coastal waters and lakes. The system was primarily required to ensure energy efficiency in its underwater section and the minimum of transmission errors. The emphasis was on non-linear distortions produced in piezoelectric transducers, an untypical source of errors.
Źródło:: Hydroacoustics; 2005, 8; 179-184
1642-1817
Pojawia się w:: Hydroacoustics
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Doppler effect in the cw fm sonar
Autorzy:: Marszal, J.
Salamon, R.
Zachariasz, K.
Schmidt, A.
Powiązania:: https://bibliotekanauki.pl/articles/331758.pdf
Data publikacji:: 2011
Wydawca:: Polskie Towarzystwo Akustyczne
Opis:: When sonars are used for military purposes they have to ensure unobtrusive operation, afeature that can be potentially secured by ‘silent sonars’ or continuous wave frequency modulation sonars (CW FM sonars). The article presents how these sonars operate and identifies the relations between their parameters. The Doppler effect and its impact on the CW FM sonar are studied to identify how it affects the sonar’s parameters. The results of simplified theoretical calculations are supported with results of computer simulations of a more realistic model.
Źródło:: Hydroacoustics; 2011, 14; 157-164
1642-1817
Pojawia się w:: Hydroacoustics
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 4.

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

Skocz do pozycji: 5.

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

Skocz do pozycji: 6.

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

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