标题： 使用探地雷达绘制树木根系的分布 显示英文标题

标题： Use of Ground Penetrating Radar to Map the Tree Roots

摘要： 树木的根系可以支持并传输养分以促进树木的地上部分健康生长，这大大提高了树木的生产力，并对维持生态系统的正常运行有显著影响。为了更高效、有效地绘制树木根系，非破坏性探地雷达被引入该领域。树木根系模型的构建主要通过存储树木根系电磁参数的剖面矩阵进行，探地雷达将归一化的一阶Blackman-Harris窗函数作为源脉冲。双程旅行时间，即电磁脉冲到达根区后反射回接收天线的时间，可以通过二维时域有限差分法计算得出。最后，将从输出的多偏移数据立方体中提取的共偏移反射数据合成 radargrams，这些 radargrams 包含关于埋藏树木根系的信息。结果表明，通过电磁脉冲与地下异常的相互作用，可以从 radargrams 中准确观察到与地下埋藏树木根系相关的分布信息，此外，除了被树木根系屏障屏蔽的中间部分，粘土层与基岩层之间的倾斜边界足够清晰以被注意到。随着雷达频率的增加，电磁脉冲会遇到严重的衰减，同时检测深度减少，因此 radargram 中的纹理逐渐模糊。这些相对准确的根系轮廓是通过数值模拟计算得出的，显示了在树木根系检测中应用探地雷达可以显著提高垂直方向上根系的分辨率。 显示英文摘要

摘要： Tree roots can support and transmit nutrients for trees healthy growth aboveground, which greatly improve trees productivity and have significant effect on maintaining the normal operation of ecosystem. In order to map the tree roots more efficiently and effectively, the nondestructive ground penetrating radar is introduced into this area. The construction of tree roots model mainly conducted by the profile matrix which stored electromagnetic parameters of tree roots, ground penetrating radar set the normalized first derivative Blackman-Harris window function as the source pulse. Two-way travel time, the electromagnetic pulses arriving at root zone and then reflected back to the receive antenna, which can be calculated by two-dimensional Finite-Difference Time-Domain. Finally synthesized the common-offset reflection data that extracted from the output multi-offset data cube as radargrams which contain the information about buried tree roots. The results turned out that through interaction between electromagnetic pulse and underground anomalies, the distribution information related subsurface buried tree roots can be observed accurately from radargrams, in addition to the intermediate section shielded by tree roots barrier, the dipping boundary between clay layer and bedrock layer is clear enough to be noticed. With the increase of radar frequency, the electromagnetic pulse meet severe attenuation accompanied by the detection depth decrease, thus the texture in radargram gradually blurred. These relatively accurate roots outline, calculated by numerical simulation, showed that the application of ground penetrating radar in tree roots detection can significantly improve resolution of roots which stretched in the vertical direction.