Effects of fast Fourier transform window size on the target strength spectra of tungsten carbide spheres
Effects of fast Fourier transform window size on the target strength spectra of tungsten carbide spheres
复制标题
快速傅里叶变换窗口大小对碳化钨球目标强度谱的影响
DOI:
10.1007/s12562-022-01653-7
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发表时间:
2023
影响因子:
1.9
通讯作者:
Kazuo Amakasu
中科院分区:
文献类型:
--
作者:
Jing Liu;Burak Saygili;Akira Iwasa;Natsuki Yamamoto;Tomohito Imaizumi;Kazuo Amakasu
The window size (WS) of the fast Fourier transform (FFT) is one of the important parameters when calculating target strength (TS) spectra from broadband echo waveforms. However, the effects of the FFT WS on TS spectra have not been thoroughly investigated. Before studying fish echoes, we thus focused on the echoes of tungsten carbide (WC) spheres, which are typically used as calibration spheres. A well-calibrated Simrad EK80 echosounder with 55–90 and 90–170-kHz linear frequency-modulated transmit signals were used for the echo sampling of WC spheres with different diameters. We calculated the TS spectra for different WSs defined by the pulse length determination level for each ping and each sphere. The calculated (measured) TS spectra were then compared with the predicted TS spectra based on the exact modal series solution. When the FFT WS was narrower, the differences between the measured and predicted TS spectra tended to increase because the ripples on the measured TS spectra became large, while the differences became small and stable above the FFT WS of approx. 0.5 m. We finally concluded that a 0.6-m FFT WS was reasonable for all cases examined herein.
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DOI:
--
发表时间:
2003
期刊:
影响因子:
--
作者:
F. Tichy;H. Solli;H. Klaveness
通讯作者:
H. Klaveness
DOI:
--
发表时间:
1992
期刊:
Fish & Fisheries Series
影响因子:
--
作者:
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E. Simmonds
DOI:
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发表时间:
2012
期刊:
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J. Zwolinski;D. Demer;Kyle A. Byers;G. Cutter;Josiah S. Renfree;Thomas S. Sessions;B. Macewicz
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B. Macewicz
影响因子:
3.3
作者:
J. Jech;K. Foote;D. Chu;L. Hufnagle
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L. Hufnagle
DOI:
--
发表时间:
2007
期刊:
--
影响因子:
--
作者:
A. Pedersen
通讯作者:
A. Pedersen