GPR Measurements for Diagnosing Tree Trunk

We developed a framework of inspecting tree trunks with ground-penetrating radar (GPR) in non-destructive manner for diagnosing the health, which have commonly been performed by drilling. The reflection measurement collects data by scanning antennas around a tree trunk, and the detailed image of internal structure is constructed by synthetic aperture radar (SAR) processing, taking the trunk shape into account. The transmission measurements allows us to distinguish heartwood and decay, which is difficult by the reflection imaging alone. The data analysis is demonstrated with synthetic data as well as a laboratory experiment with a log. We also present the developed framework applied to a tree inspection project for very old trees in a shrine. We successfully obtained reasonable results, which are consistent with the visual inspection results.