Micro Polarimetric Borehole Radar for Subsurface Fracture Measurement

用于地下裂缝测量的微偏振钻孔雷达

• 批准号: 10450389
• 负责人: SATO Motoyuki
• 金额: $ 8.13万
• 依托单位: TOHOKU UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (B)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10450389/
• 关键词: Radar Polarimetry; Borehole Radar; Cross-hole radar; Optical Analog signal link; Civil Engineering; Rock Stability Monitoring; Fracture Imaging; Fracture Characterization; ステップ周波数レーダ; 光アナログ信号伝達

Polarimetric borehole radar has a good potential for detecting and evaluating radar targets beyond the radar resolution determined by the wavelength. This is a great advantage for borehole radar, which is often used I lossy subsurface material. In this research project, we have developed a polarimetric borehole radar system which operates under 200MHz, and can be installed in boreholes having a diameter less than 5cm.In order to have a thin down hole sonde, we have developed a optical analog signal link which is equipped in a cylindrical casing of 2cm in diameter. The completed polarimetric borehole radar system has a diameter of 41 mm. This system was evaluated in field test and could show it can acquire polarimetric radar signal. At the same time, we found that the signal acquired by borehole radar, whose diameter is much smaller than that of a borehole is unstable, and we need additional equipment to set the down hole sonde at the center of the borehole.Polarimetric borehole radar measurements were carried out in several test sites including Mirror Lake, USA, Asse, Germany and Hirabayashi, Japan. We showed that he full-polarimetric borehole radar profiles can be used for classification of subsurface fractures. Under certain conditions, we found that the water permeability is related to the surface roughness of the subsurface fractures, and the polarimetric borehole radar can evaluate them.By using the cross-hole borehole radar measurement, we proposed a imaging technique based on migration. This technique can achieve higher resolution that the conventional tomography analysis.

极化钻孔雷达具有良好的潜力，可以检测和评估超出波长确定的雷达分辨率的雷达靶标。对于井眼雷达来说，这是一个很大的优势，通常使用我有损失的地下材料。在该研究项目中，我们开发了一个极化的钻孔雷达系统，该系统在200MHz下运行，并且可以安装在直径小于5cm的钻孔中，以便在5厘米处进行，以使其具有较薄的孔孔，我们已经开发了一个光学模拟信号链路配备直径为2厘米的圆柱壳。完整的极化钻孔雷达系统的直径为41毫米。该系统在现场测试中进行了评估，可以表明它可以获取极化雷达信号。同时，我们发现井眼雷达获得的信号（其直径远小于钻孔的信号是不稳定的，我们需要其他设备来设置井眼中心的孔孔。极性钻孔雷达雷达测量值是在包括美国，美国，德国和日本Hirabayashi的几个测试地点进行的。我们表明他可以将其全钟钻孔雷达轮廓用于地下骨折分类。在某些条件下，我们发现水的渗透性与地下骨折的表面粗糙度有关，并且偏振钻孔的雷达可以评估它们。通过使用跨孔钻孔雷达测量，我们提出了一种基于迁移的成像技术。该技术可以实现与常规层析成像分析更高的分辨率。

项目成果

H. Zhou and M. Sato: "Fracture Imaging and Saline Tracer Detection by Crosshole Borehole Radar Data Migration"Proceedings of the 8th Int. Conference on Ground Penetrating Radar, Gold Coast, Australia. (2000)

H. Zhou 和 M. Sato：“通过跨孔钻孔雷达数据迁移进行裂缝成像和盐水示踪剂检测”第八届国际会议论文集。

M.Sato and M.Takeshita: "Polarimetric Borehole Radar Approach to Subsurface Fracture Classification"Proceedings of the 8th Int. Conference on Ground Penetrating Radar. (印刷中). (2000)

M.Sato 和 M.Takeshita：“极化钻孔雷达方法进行地下裂缝分类”第八届探地雷达国际会议论文集（2000 年）。

H.Zhou and M.Sato: "Estimation of Subsurface Fracture Extension by Using Cross-hole Radar Measurement"信学技報. SANE99-73. 81-85 (1999)

H.Zhou 和 M.Sato：“使用跨孔雷达测量估计地下裂缝延伸”SANE99-73 (1999)。

M.Sato and T.Miwa: "Polarimetric Borehole Radar System for Fracture Measurement"Subsurface Sensing Technologies and Applications. 1. 161-174 (2000)

M.Sato 和 T.Miwa：“用于裂缝测量的极化钻孔雷达系统”地下传感技术和应用。

M. Sato: "Polarimetric Borehole Radar Approach to Subsurface Fracture Classification"Proc. Three-Dimensional Electromagnetics, Salt Lake City. 259-262. 26-29 (1999)

M. Sato：“极化钻孔雷达地下裂缝分类方法”Proc。