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1

An acoustic sea glider for deep-sea noise profiling using an acoustic vector sensor

Sun Qindong, Zhou Hongkun

Polish Maritime Research

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2022

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nr 1

57--62

EN

An acoustic sea glider has been developed for ambient sea noise measurement and target detection through the deployment of an acoustic vector sensor (AVS). The glider was designed with three cabins connected in sequence and it can dive to depths exceeding 1200m. The AVS fixed on the glider measure acoustic pressure and particle velocities related to undersea noise, and the inner attitude sensors can effectively eliminate the estimation deviation of the direction of arrival. The inherent self-noises of the acoustic sea glider and AVS are presented respectively in respect to the Knudsen spectra of sea noise. Sea trial results indicate that the AVS could work well for undersea noise measurement when the glider is smooth sliding, and the target azimuth estimated by AVS after correction is remarkably consistent with the values measured by the GPS, and direction-finding errors are less than 10 degrees. The research in this paper shows that the acoustic sea glider is able to undertake tasks such as a wide range of underwater acoustic measurement and detection.

2

Automatic target recognition of complex internal structure

Niedziela T.

Archives of Transport

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2014

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Vol. 32, iss. 4

61--72

EN

The paper presents methods of automatic target recognition from images with complex internal structure. Recognition methods proposed are based on the Fourier transform properties. These methods make it possible to bring the problem to Fourier transform, feature extraction and input image classification. Image data synthesis within diffraction plane significantly increases the probability of target detection.

3

Modelling and evaluation of bistatic radar systems' capabilities

Nowak T., Mazur M., Pędziwiatr J., Nalewaja A., Sankowski M.

Elektronika : konstrukcje, technologie, zastosowania

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2011

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Vol. 52, nr 12

81-85

EN

In that paper capabilities of bistatic radar systems are presented. Single independent receiver is described, including the antenna system parameters and their impact on whole system performance. The operation of single receiver with a PSR (Primary Surveillance Radar) is simulated for several realistic scenarios and system parameters, which enables to point out advantages and disadvantages of single receiver. Then a bistatic radar network using the TDOA method is briefly described. Simulations performed for the same scenarios show substantially better performance of the network of bistatic receivers, as compared with the capabilities of the single receiver. Finding a bistatic radar network relatively cheap solution for extending radar range and increasing detection quality some practical applications were also proposed.

PL

W artykule przedstawiono zdolności bistatycznych systemów radarowych. Scharakteryzowano pojedynczy odbiornik bistatyczny, w tym wpływ parametrów anten na cechy funkcjonalne systemu. Działanie pojedynczego odbiornika współpracującego z radarem ATC zostało zasymulowane dla różnych realistycznych scenariuszy, różnych parametrów systemu oraz celów. Na tej podstawie oceniono wady i zalety pojedynczego odbiornika. Symulacje przeprowadzone dla sieci odbiorników bistatycznych, wykorzystujących metodę TDOA do określenia pozycji celów, wykazały większe możliwości sieci odbiorników w porównaniu do pojedynczego odbiornika. Ponieważ sieć radarów bistatycznych stanowi względnie tanie rozwiązanie, pozwalające na zwiększenie zasięgu radarów pierwotnych omówiono ich przykładowe aplikacje.