Temat: sonar - Katalog OPAC zbiorów

Skocz do pozycji: 1.

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: 2.

Tytuł:: Detection Range of Intercept Sonar for CWFM Signals
Autorzy:: Marszal, J.
Salamon, R.
Powiązania:: https://bibliotekanauki.pl/articles/176394.pdf
Data publikacji:: 2014
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: intercept sonar
silent sonar
CWFM signal
detection
detection range
Opis:: Stealth in military sonars applications may be ensured through the use of low power signals making them difficult to intercept by the enemy. In recent years, silent sonar design has been investigated by the Department of Marine Electronic Systems of the Gdansk University of Technology. This article provides an analysis of how an intercept sonar operated by the enemy can detect silent sonar signals. To that end a theoretical intercept sonar model was developed with formulas that can numerically determine the intercept ranges of silent sonar sounding signals. This was tested for a variety of applications and water salinities. Because they are also presented in charts, the results can be used to compare the intercept ranges of silent sonar and traditional pulse sonar.
Źródło:: Archives of Acoustics; 2014, 39, 2; 215-230
0137-5075
Pojawia się w:: Archives of Acoustics
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 3.

Tytuł:: Analysis of distance measurement errors in CW FM sonar with MLS code modulation
Autorzy:: Jedel, A.
Marszal, J.
Salamon, R.
Powiązania:: https://bibliotekanauki.pl/articles/331626.pdf
Data publikacji:: 2017
Wydawca:: Polskie Towarzystwo Akustyczne
Tematy:: CW FM sonar
pseudorandom sequence
Doppler effect
sonar parameters
Opis:: Although used in the classic silent sonar, the CW FM sounding signal has a major flaw which is its inaccuracy in determining the distance to a target. The authors of the article have developed a concept of silent sonar using frequency modulation signals switched by pseudorandom codes, already discussed in their previous work. This article presents a detailed analysis of errors in CW FM sonar with pseudo-random sequence code modulation confronted with errors which occur in similar sonar without code modulation.
Źródło:: Hydroacoustics; 2017, 20; 75-84
1642-1817
Pojawia się w:: Hydroacoustics
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 4.

Tytuł:: Bearing errors in passive sonar stationary target location
Autorzy:: Schmidt, A.
Marszal, J.
Salamon, R.
Jedel, A.
Ostrowski, Z.
Powiązania:: https://bibliotekanauki.pl/articles/332830.pdf
Data publikacji:: 2009
Wydawca:: Polskie Towarzystwo Akustyczne
Tematy:: bearing errors
passive sonar
hydroacoustics
Opis:: The paper presents a method for determining the coordinates of stationary targets using passive sonar bearing. It identifies the requirements sonar movements must meet to keep the incorrect determination of coordinates to a minimum. It gives the relations, which help determine coordinate errors analytically. Numerical experiments are used to demonstrate the success of the analysis.
Źródło:: Hydroacoustics; 2009, 12; 189-200
1642-1817
Pojawia się w:: Hydroacoustics
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 5.

Tytuł:: Mutual Clutter Suppression Techniques for FM Sonars
Autorzy:: Marszal, J.
Rudnicki, M.
Jedel, A.
Salamon, R.
Kochańska, I.
Powiązania:: https://bibliotekanauki.pl/articles/176495.pdf
Data publikacji:: 2016
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: sonar
signal processing
FM
LFM
HFM
clutter
crosstalk
Opis:: The article presents methods that help in the elimination of mutual clutter as well as the consequences of two FM sounding signal sonars operating in the same body of water and frequency band. An in-depth analysis of mutual clutter was carried out. The effects of sounding signal differentiation were determined, as was the Doppler effect on mutual clutter suppression. One of the methods analysed is of particular interest in a situation in which collaborating sonars are operating in opposite frequency modulation directions. This method is effective for both linear and hyperbolic frequency modulations. A formula was derived, identifying exactly how much quantities of clutter may be lessened. The work included comprehensive computer simulations and measurements as well as tests in real-life conditions.
Źródło:: Archives of Acoustics; 2016, 41, 4; 721-729
0137-5075
Pojawia się w:: Archives of Acoustics
Dostawca treści:: Biblioteka Nauki

Artykuł

Skocz do pozycji: 6.

Tytuł:: Distance measurement errors in silent FM-CW sonar with matched filtering
Autorzy:: Marszal, J.
Salamon, R.
Powiązania:: https://bibliotekanauki.pl/articles/220637.pdf
Data publikacji:: 2012
Wydawca:: Polska Akademia Nauk. Czytelnia Czasopism PAN
Tematy:: silent sonar
frequency modulation
continuous wave
matched filtering
distance measurement
errors
Doppler effect
Opis:: The secretiveness of sonar operation can be achieved by using continuous frequency-modulated sounding signals with reduced power and significantly prolonged repeat time. The application of matched filtration in the sonar receiver provides optimal conditions for detection against the background of white noise and reverberation, and a very good resolution of distance measurements of motionless targets. The article shows that target movement causes large range measurement errors when linear and hyperbolic frequency modulations are used. The formulas for the calculation of these errors are given. It is shown that for signals with linear frequency modulation the range resolution and detection conditions deteriorate. The use of hyperbolic frequency modulation largely eliminates these adverse effects.
Źródło:: Metrology and Measurement Systems; 2012, 19, 2; 321-332
0860-8229
Pojawia się w:: Metrology and Measurement Systems
Dostawca treści:: Biblioteka Nauki

Artykuł

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