Since tree roots are important to ecosystems, particularly in the context of global climate change, better understanding of their organization is necessary. Ground-penetrating radar (GPR) appears a useful tool to that effect. In this contribution, a novel processing procedure to reconstruct 3-D root architectures from GPR data in heterogeneous environments is proposed, involving three main steps: 1) noise-related information is removed using singular value decomposition (SVD); 2) a modified version of randomized Hough transform (RHT) yields the soil dielectric constant; and 3) a matched-filter technique combined with Hilbert transform then operates as wave migration. Viability is first studied from comprehensive numerical simulations carried out with the gprMax software on a realistic root model in a 3-D heterogeneous environment. The heterogeneous soil effect is studied carefully through a number of simulations involving six different soil types. Then, controlled laboratory measurements are conducted on a root prototype using a bistatic GPR system involving folded complementary bowtie antennas in the frequency range of 300 MHz to 3.3 GHz. The 3-D results from both simulations and experiments show the good performance and potential of the proposed processing.

中文翻译：

---

非均质土壤条件下探地雷达重建树根的处理框架

由于树根对于生态系统至关重要，尤其是在全球气候变化的背景下，因此有必要更好地了解其组织。探地雷达（GPR）似乎是实现这一目标的有用工具。在这一贡献中，提出了一种在异构环境中从GPR数据重构3-D根架构的新颖处理过程，包括三个主要步骤：1）使用奇异值分解（SVD）去除与噪声相关的信息；2）随机霍夫变换（RHT）的修改版本产生土壤介电常数；3）匹配滤波器技术与希尔伯特变换相结合，然后作为波迁移。首先使用gprMax软件在3D异构环境中的真实根模型上通过全面的数值模拟研究了生存能力。通过涉及六种不同土壤类型的大量模拟，仔细研究了异质土壤效应。然后，使用双基地GPR系统在根原型上进行受控的实验室测量，该系统包括频率范围为300 MHz至3.3 GHz的折叠式互补领结天线。来自仿真和实验的3-D结果显示了拟议处理的良好性能和潜力。