Design and Convergence Performance Analysis of Aspherical Acoustic Lens Applied to Ambient Noise Imaging in Actual Ocean Experiment

2011 ◽  
Vol 50 (7) ◽  
pp. 07HG09 ◽  
Author(s):  
Kazuyoshi Mori ◽  
Hanako Ogasawara ◽  
Toshiaki Nakamura ◽  
Takenobu Tsuchiya ◽  
Nobuyuki Endoh
Keyword(s):  
Performance Analysis ◽  
Ambient Noise ◽  
Acoustic Lens ◽  
Convergence Performance

Design and Convergence Performance Analysis of Aspherical Acoustic Lens Applied to Ambient Noise Imaging in Actual Ocean Experiment

2011 ◽  
Vol 50 (7S) ◽  
pp. 07HG09 ◽  
Author(s):  
Kazuyoshi Mori ◽  
Hanako Ogasawara ◽  
Toshiaki Nakamura ◽  
Takenobu Tsuchiya ◽  
Nobuyuki Endoh
Keyword(s):  
Performance Analysis ◽  
Ambient Noise ◽  
Acoustic Lens ◽  
Convergence Performance

scholarly journals Performance Analysis and Design Considerations of the Shallow Underwater Optical Wireless Communication System with Solar Noises Utilizing a Photon Tracing-Based Simulation Platform

Electronics ◽  
2021 ◽  
Vol 10 (5) ◽  
pp. 632
Author(s):  
Xiaozheng Wang ◽  
Minglun Zhang ◽  
Hongyu Zhou ◽  
Xiaomin Ren
Keyword(s):  
Performance Analysis ◽  
Wireless Communication ◽  
Ambient Noise ◽  
Large Scale ◽  
Delay Spread ◽  
Simulation Platform ◽  
Optical Wireless Communication ◽  
Optical Wireless ◽  
Analysis And Design ◽  
The Impact

The performance of the underwater optical wireless communication (UOWC) system is highly affected by seawater´s inherent optical properties and the solar radiation from sunlight, especially for a shallow environment. The multipath effect and degradations in signal-to-noise ratio (SNR) due to absorption, scattering, and ambient noises can significantly limit the viable communication range, which poses key challenges to its large-scale commercial applications. To this end, this paper proposes a unified model for underwater channel characterization and system performance analysis in the presence of solar noises utilizing a photon tracing algorithm. Besides, we developed a generic simulation platform with configurable parameters and self-defined scenarios via MATLAB. Based on this platform, a comprehensive investigation of underwater channel impairments was conducted including temporal and spatial dispersion, illumination distribution pattern, and statistical attenuation with various oceanic types. The impact of ambient noise at different operation depths on the bit error rate (BER) performance of the shallow UOWC system was evaluated under typical specifications. Simulation results revealed that the multipath dispersion is tied closely to the multiple scattering phenomenon. The delay spread and ambient noise effect can be mitigated by considering a narrow field of view (FOV) and it also enables the system to exhibit optimal performance on combining with a wide aperture.

Extraction of Target Scatterings from Received Transients on Target Detection Trial of Ambient Noise Imaging with Acoustic Lens

2012 ◽  
Vol 51 (7S) ◽  
pp. 07GG10 ◽  
Author(s):  
Kazuyoshi Mori ◽  
Hanako Ogasawara ◽  
Toshiaki Nakamura ◽  
Takenobu Tsuchiya ◽  
Nobuyuki Endoh
Keyword(s):  
Target Detection ◽  
Ambient Noise ◽  
Acoustic Lens

THEORY OF ACOUSTIC IMAGING IN THE OCEAN WITH AMBIENT NOISE

1993 ◽  
Vol 01 (01) ◽  
pp. 117-140 ◽  
Author(s):  
MICHAEL J. BUCKINGHAM
Keyword(s):  
Ambient Noise ◽  
Imaging System ◽  
Sole Source ◽  
Acoustic Imaging ◽  
Accurate Approximation ◽  
Theoretic Analysis ◽  
Acoustic Lens ◽  
Full Wave ◽  
Line Array ◽  
Incoherent Imaging

Following a recent experiment in which ambient noise (acoustic daylight) was used as the sole source of acoustic illumination for detecting objects in the ocean, a full wave-theoretic analysis is presented in this article of the visibility of a pressure-release spherical target when illuminated by ambient noise showing various degrees of anisotropy. The basis of the analysis is a new, accurate approximation for the Green's function representing the field around the sphere. From this expression, an analysis of the acoustic contrast is developed, as observed at the output of an endfire line array, which constitutes the acoustic lens. Our essential conclusion is that, even in isotropic noise, which presents one of the least favourable conditions for incoherent imaging, the visibility of the sphere (i.e. the ratio of intensities with the sphere present and absent) is approximately 4 dB. This is consistent with our early experimental observations, and is adequate to form the basis of an acoustic daylight imaging system.

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