2004 Fiscal Year Final Research Report Summary
Basic studies on cavity and buried object detection from borehole radar data by using FBTS method
| Project/Area Number |
15560361
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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 |
Measurement engineering
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| Research Institution | Nagasaki University |
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Principal Investigator |
ZHOU H. Nagasaki University, Faulty of Engineering, Research associate, 工学部, 助手 (20346927)
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| Co-Investigator(Kenkyū-buntansha) |
TAKENAKA T. Nagasaki University, Faulty of Engineering, professor, 工学部, 教授 (40117156)
TANAKA T. Nagasaki Univ., Graduate School of Science & Technology, Associate professor, 大学院・生産科学研究科, 助教授 (50202172)
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| Project Period (FY) |
2003 – 2004
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| Keywords | Subsurface exploration / FBTS method / Inverse problem / Antenna / Borehole radar |
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| Research Abstract |
The research group has developed a method for reconstructing 2D and 3D lossy objects with high contrast by using time-domain microwave data.
During the term of research we have carried out following research activities. (1)Simultaneous reconstructions of relative permittivity and conductivity of a 3D lossy object have succeeded from simulated data by taking the length of dipole antennas into account. (2)The 3D FBTS method has been applied to reconstruct a 2D lossless cylinder from experiment data excited and received by dipole antennas. In order to speed up the reconstruction, the received data are transformed into the data as if transmitted and received by ideal dipoles. Thus the forward simulation by using FDTD method for one transmitter and multiple receivers can be carried out simultaneously without the influence of coupling among the receiving dipole antennas. Then the transformed data are used in reconstruction. Reconstructed result is consistent with the known object both in the value of permittivity, and in the shape and size. (3)Migration velocity analysis by using genetic algorithm has been applied to field common transmitter ground penetrating data. From the distribution of relative permittivity obtained from velocity analysis the distribution of water content has been obtained. It is consistent with geological information obtained by other means.
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