概述了钻孔雷达的主要应用领域和在探测地下孔洞、地下裂缝等方面的优势,并介绍了相关技术在国内外的发展现状,同时对钻孔雷达天线设计的难点和特殊性进行了说明。文中介绍了天线的自行设计实例,同时用实验中测量的驻波比VSWR等参数分析了天线的匹配特性,并构建了三维天线模型,将设计实例中的天线基于时域有限差分法对其方向性能进行仿真,其方向性优于标准值。在设计的水槽实验中测试本天线架构的钻孔雷达系统,获得了满意的测量数据。分析检验了整个系统和天线的工作状况,实验表明天线主要性能满足设计和工程应用要求,可应用于实际勘探;并对采用本天线的钻孔雷达系统的探测能力和应用前景进行了评估,钻孔雷达系统在花岗岩、石灰岩等岩层中的探测距离可到几十米至100m。
The authors generalized the main application field of borehole radar and its advantages in detecting undergroud holes and cracks, introduced the current situation of related technologies at home and abroad, and also illustrated the difficulties and particularities of borehole radar antenna design. Self design example of antenna is introduced in this paper, and the matching property of antenna has been analyzed by VSWR and other parameters measured in experiments and established 3D antenna model to imitate the directional property of antenna based on finite-difference time-domain method design example showing the directivity superior to the standard value. Borehole radar system built by this antenna is used in flume experiment and obtained satisfied results. The working situation of whole system and antenna have been analyzed and tested, the results show the main property of antenna meet to design and application requirements, which can be used to practical exploration. The evaluation results of borehole radar system's detection ability and application prospect using this antenna show the detection distance of borehole radar system in granite and limestone is several decameter to 100 m.