Wyniki wyszukiwania - BazTech

1

Compression algorithms for multibeam sonar records

Chybicki A., Moszyński M., Poćwiardowski P.

Hydroacoustics

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2008

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Vol. 11

55-62

EN

Operational requirements of multibeam sonar systems result in very large volumes of datasets stored on local hard drives of operator's station. In this context, the process of archiving acquired data becomes a crucial problem. The paper investigates various lossy and lossless compression methods that can be applied to multibeam sonar data to reduce the size of acquired files without loosing relevant information. The specific character of MBS data allows applying various signal, image and video compression methods to achieve better results than when using standard compression tools. Various techniques of reordering the data were analyzed to achieve best possible compression ratio.

2

Single side band modulation and bandpass subsampling

Poćwiardowski P., Kobylarz P.

Hydroacoustics

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2001

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Vol. 4

201--204

EN

Paper describes the efficient method of gaining information from beamformer based on band subsampling technique. In active sonar systems, where centre (carrier) frequency is known (neglecting the Doppler shift), it is feasible to use the subsampling techniques, widely used elsewhere. The subsampling techniques can be used for narrow band signals. One of the advantages of this method lays in the use of noiseless heterodyne in mixer circuit, which provides errorless signal shifting to zero frequency. The use of subsampling provides good opportunity for decreasing the amount of digital processing, hardware components and followed by capital expenditure consumed during fabrication of sonars systems. lt also allows increasing the spatial resolution of sonar by increasing the number of preformed beams in the sonar array.

3

Application of acoustic streaming for improving metal diffusion during electrochemical deposition

Poćwiardowski P., Stepnowski A., Bjørnø L.

Hydroacoustics

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2001

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Vol. 4

205--208

EN

The efficient method of improving diffusion of more noble metal through barrier layer created during electrochemical deposition process, by means of acoustic streaming was investigated. The results obtained from the experiments demonstrates the possibility of controlling the amount of liquid injected to the vicinity of cathode by the change of acoustic intensity. This results in accomplishing the controlled migration inside barrier layer and thus the inspecting of the mass of more noble metal in the plated alloy. The Schlichting type of acoustic streaming was mostly used in investigation.

4

System telemonitoringu wód Zatoki Gdańskiej

Poćwiardowski P., Podliński J., Pomianowski K., Marcinowicz K.

Elektronizacja : podzespoły i zastosowania elektroniki

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2000

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nr 2

9-11