| Project/Area Number |
11650351
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
電子デバイス・機器工学
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| Research Institution | Kumamoto University |
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Principal Investigator |
NISHIMOTO Masahiko Graduate School of Science, Kumamoto University Associate Professor, 大学院・自然科学研究科, 助教授 (60198520)
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| Co-Investigator(Kenkyū-buntansha) |
NAKA Yoshihiro Faculty of Engineering, Kumamoto University Research Associate, 工学部, 助手 (30305007)
IKUNO Hiroyoshi Faculty of Engineering, Kumamoto University Professor, 工学部, 教授 (80040400)
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| Project Period (FY) |
1999 – 2000
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| Project Status |
Completed (Fiscal Year 2000)
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| Budget Amount *help |
¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 2000: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1999: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | wavelet transform / time-frequency analysis / electromagnetic scattering / signal processing / short-time Fourier transform / ウエーブレット変換 |
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| Research Abstract |
In order to analyze scattering responses from radar targets, a new method for time-frequency analysis of radar echoes using the wavelet transform is proposed. The advantage of this method is that it can provide an adaptive spectrogram of signals. Unlike the short-time Fourier transform and the conventional wavelet transform, the time and frequency resolution and are adjusted to best match the signal. Therefore, an adaptive spectrogram, a new signal energy distribution in the joint time-frequency domain, can be obtained. Of course, this new signal energy distribution is non-negative, cross-term interference free, and of high resolution. In order to demonstrate the effectiveness of this method, numerical simulations are presented. As a results, following results are obtained :
1. The present method is effective compare with other time-frequency techniques such as the short-time Fourier transform and conventional wavelet analysis, because it can provides an adaptive spectrogram.
2. Time and frequency resolution can be controlled by the appropriate selection of the parameters of basis functions.
3. The effects of noise included in radar signals can be decreased by the appropriate selection of the signal decomposition level.
4. The curved lines indicating the frequency dispersion cannot be displayed clearly in the time-frequency plane for the analysis of frequency dispersive signals. This problem is currently under investigation.
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