| 講演要旨(和文) | | 地中レーダは浅部地下探査を行うための手法であり、金属探査・地雷探査など多くの分野で用いられている。地中レーダは分解能が高いという長所があるが、可探深度が地下数mと浅いことが欠点である。そこで本研究では、この欠点を解消するために、現在主流であるボウタイアンテナの形状を改良し、それぞれの性能の比較を行うことによってより深い可探深度を持つアンテナを開発することを目的とした。評価を行うに当たり、受信データにマイグレーションを適用した。その結果、螺旋状のアンテナであるスパイラルアンテナの有用性を示すことができた。 |
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| | 講演要旨(英文) | | Ground-penetrating radar (GPR) is a survey method used for investigating shallow underground structure. Although GPR has high resolution, it gives us limited information for a depth of a few meters. On the basis of the previous field studies, the penetration depth of GPR depends on the shape of its antenna. Also, seismic research proved that data acquisition and processing could improve the resolution if we design a survey to assure the resolution improvement. In this study, we confirm how the shape of antenna improves the performance of GPR that considered antenna's shape and, how the depth of penetration could be improved using the existing antennas. We focus the spiral antenna, and compare the performance with conventional antennas. We compared their radiation pattern and amplitude of received waves using numerical simulations. Then, for discussion of the efficiency on the field survey, we numerically obtained received data set along profiles and analyze the subsurface image using the migration technique. For these numerical studies, we use the FDTD Method. Consequently, we can show the high ability of spiral antenna for deep imaging with GPR Also, we confirmed that the introduction of 3D survey and processing, the depth of investigation could be improved. |
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