A processing framework for tree rootsreconstruction using Ground-Penetrating Radarunder heterogeneous soil conditions

International audienceSince tree roots are important to ecosystems, particularlyin the context of global climate change, better understandingtheir organization is necessary. Ground-penetrating radar(GPR) appears a useful tool to that effect. In this contribution, anovel processing procedure to reconstruct 3D root architecturesfrom GPR data in heterogeneous environments is proposed,involving three main steps: (i) noise-related information is removedusing Singular Value Decomposition (SVD), (ii) a modifiedversion of Randomized Hough Transform (RHT) yields the soildielectric constant, (iii) a matched filter technique combined withHilbert Transform then operates as wave migration. Viability isfirst studied from comprehensive numerical simulations carriedout with gprMax software on a realistic root model in a 3Dheterogeneous environment. The heterogeneous soil effect isstudied carefully through a number of simulations involving sixdifferent soil types. Then, controlled laboratory measurementsare conducted on a root prototype using a bi-static GPR systeminvolving folded complementary bowtie antennas in the 300 MHzto 3.3 GHz frequency range. 3D results from both simulationsand experiments show the good performance and potential of theproposed processing