Effect of the Outer Pipe on Reducing Direct Coupling of the Thin Borehole Radar Probe in Thick Water-Filled Borehole
We propose an outer pipe to reduce a direct wave in a thin single-hole borehole radar probe in a thick water-filled borehole. The outer pipe replaces the medium, such as water inside the borehole, with low-permittivity materials, such as air and plastics. According to numerical calculations, the cyl...
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| Format: | Article |
| Language: | English |
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MDPI AG
2024-12-01
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| Series: | Remote Sensing |
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| Online Access: | https://www.mdpi.com/2072-4292/17/1/100 |
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| author | Satoshi Ebihara Raiki Masui Koki Koyama Yuki Tsujikawa Yuto Nishida |
| author_facet | Satoshi Ebihara Raiki Masui Koki Koyama Yuki Tsujikawa Yuto Nishida |
| author_sort | Satoshi Ebihara |
| collection | DOAJ |
| description | We propose an outer pipe to reduce a direct wave in a thin single-hole borehole radar probe in a thick water-filled borehole. The outer pipe replaces the medium, such as water inside the borehole, with low-permittivity materials, such as air and plastics. According to numerical calculations, the cylindrical water layer makes the direct wave from the transmitting loop antenna to the receiving one have significant power and narrow frequency bandwidth. This is caused by the low attenuation of the TE<sub>01</sub> surface wave when there is a cylindrical water layer. The MoM analysis showed that wearing the outer pipe on the radar probe decreased the direct wave’s power more than the reflected wave from the subsurface objects, improving the detection of that reflected wave. We realized the radar system with the outer pipe by attaching the two acrylic pipes with different diameters. With this outer pie, we conducted field experiments to estimate the position of metal ore near the borehole in skarn with the loop antenna array type borehole radar. The direct wave having oscillation prevented the detection of the reflected wave from the sphalerite vein in the time domain without the outer pipe. However, attaching the outer pipe highlighted that reflected wave. |
| format | Article |
| id | doaj-art-47d9eebde11b4afc90b77e6cd0ac8805 |
| institution | Kabale University |
| issn | 2072-4292 |
| language | English |
| publishDate | 2024-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Remote Sensing |
| spelling | doaj-art-47d9eebde11b4afc90b77e6cd0ac88052025-01-10T13:20:13ZengMDPI AGRemote Sensing2072-42922024-12-0117110010.3390/rs17010100Effect of the Outer Pipe on Reducing Direct Coupling of the Thin Borehole Radar Probe in Thick Water-Filled BoreholeSatoshi Ebihara0Raiki Masui1Koki Koyama2Yuki Tsujikawa3Yuto Nishida4Department of Electrical and Electronic Engineering, Osaka Electro-Communication University, Neyagawa 572-8530, JapanDepartment of Electrical and Electronic Engineering, Osaka Electro-Communication University, Neyagawa 572-8530, JapanDepartment of Electrical and Electronic Engineering, Osaka Electro-Communication University, Neyagawa 572-8530, JapanDepartment of Electrical and Electronic Engineering, Osaka Electro-Communication University, Neyagawa 572-8530, JapanDepartment of Electrical and Electronic Engineering, Osaka Electro-Communication University, Neyagawa 572-8530, JapanWe propose an outer pipe to reduce a direct wave in a thin single-hole borehole radar probe in a thick water-filled borehole. The outer pipe replaces the medium, such as water inside the borehole, with low-permittivity materials, such as air and plastics. According to numerical calculations, the cylindrical water layer makes the direct wave from the transmitting loop antenna to the receiving one have significant power and narrow frequency bandwidth. This is caused by the low attenuation of the TE<sub>01</sub> surface wave when there is a cylindrical water layer. The MoM analysis showed that wearing the outer pipe on the radar probe decreased the direct wave’s power more than the reflected wave from the subsurface objects, improving the detection of that reflected wave. We realized the radar system with the outer pipe by attaching the two acrylic pipes with different diameters. With this outer pie, we conducted field experiments to estimate the position of metal ore near the borehole in skarn with the loop antenna array type borehole radar. The direct wave having oscillation prevented the detection of the reflected wave from the sphalerite vein in the time domain without the outer pipe. However, attaching the outer pipe highlighted that reflected wave.https://www.mdpi.com/2072-4292/17/1/100directional borehole radarloop array antennadirect waveSommerfeld integral |
| spellingShingle | Satoshi Ebihara Raiki Masui Koki Koyama Yuki Tsujikawa Yuto Nishida Effect of the Outer Pipe on Reducing Direct Coupling of the Thin Borehole Radar Probe in Thick Water-Filled Borehole Remote Sensing directional borehole radar loop array antenna direct wave Sommerfeld integral |
| title | Effect of the Outer Pipe on Reducing Direct Coupling of the Thin Borehole Radar Probe in Thick Water-Filled Borehole |
| title_full | Effect of the Outer Pipe on Reducing Direct Coupling of the Thin Borehole Radar Probe in Thick Water-Filled Borehole |
| title_fullStr | Effect of the Outer Pipe on Reducing Direct Coupling of the Thin Borehole Radar Probe in Thick Water-Filled Borehole |
| title_full_unstemmed | Effect of the Outer Pipe on Reducing Direct Coupling of the Thin Borehole Radar Probe in Thick Water-Filled Borehole |
| title_short | Effect of the Outer Pipe on Reducing Direct Coupling of the Thin Borehole Radar Probe in Thick Water-Filled Borehole |
| title_sort | effect of the outer pipe on reducing direct coupling of the thin borehole radar probe in thick water filled borehole |
| topic | directional borehole radar loop array antenna direct wave Sommerfeld integral |
| url | https://www.mdpi.com/2072-4292/17/1/100 |
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