| Project/Area Number |
06555108
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| Research Category |
Grant-in-Aid for Scientific Research (A)
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| Allocation Type | Single-year Grants |
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| Section | 試験 |
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| Research Field |
情報通信工学
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| Research Institution | KYOTO UNIVERSITY |
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Principal Investigator |
SATO Toru Kyoto University, Graduate School of Electronics and Communication, Associate Professor, 工学研究科, 助教授 (60162450)
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| Co-Investigator(Kenkyū-buntansha) |
SHINBO Tetsuya Komatsu Co.Ltd.Research Scientist, 研究員
KASAHARA Yoshiya Kyoto University, Graduate School of Electronics and Communication, Research Ass, 工学研究科, 助手 (50243051)
KIMURA Iwane Osaka Institute of Technology, Faculty of Information Science, Professor, 情報科学部, 教授 (00025884)
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| Project Period (FY) |
1994 – 1996
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| Project Status |
Completed (Fiscal Year 1996)
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| Budget Amount *help |
¥7,100,000 (Direct Cost: ¥7,100,000)
Fiscal Year 1996: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1995: ¥2,700,000 (Direct Cost: ¥2,700,000)
Fiscal Year 1994: ¥3,500,000 (Direct Cost: ¥3,500,000)
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| Keywords | subsurface remote sensing / high-resolution radar / radar signal processing / discrete model fitting / inhomogeneous media |
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| Research Abstract |
For an accurate imaging of subsurface objects, it is essential to develop an algorithm which can handle the effect of strong clutter and the dispersive medium. While it is very hard to include the effect of loss and dispersion in inverse scattering problems, various numerical procedures have already been developed for the forward scattering case. Our approach has been to model the target with a limited number of parameters, and to recursively modify it so that the observed signal waveforms fit the estimated ones computed for the model. In order to save the machine time, we compute the estimated scattered wave by using a modified ray tracing method which include the effect of diffraction.
Our previous algorithm is, however, applicable only to the case of lossless and non-dispersive medium. In this work, we extended it to handle a more realistic case of target imaging in a two-dimensional homogeneous lossy and dispersive medium. The attenuation and dispersion of the transmitted waveform is taken care of by applying proper filter functions which are synthesized in the frequency domain. The model parameters to be determined are the permittivity and conductivity of the medium, their frequency derivatives, and the location of several points that characterize the outer contour of the object.
The performance of the developed algorithm is quantitatively wexamined by numerical simulations. The simulated data are generated using the Frequency-Dependent FDTD method. Target shapes assumed are conductive cylinders and plates whose size is a few wavelengths at the center frequency of the pulse. In order to examine the tolerance of the algorithm against clutters, 200 point targets with various permittivity are randomly embedded in the simulated medium. It is found that the algorithm can accurately reconstruct the target shape for the signal-to-clutter ratio of larger than 10dB,and the size can be correctly estimated even with S/C of 4dB.
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