Estimation of Biomass of the tree roots from the 3D image obtained by GPR

A new approach for estimation of tree root biomass by using a GPR system with a high accuracy positioning system is proposed. 3D images of subsurface can be obtained clearly with this system, which we refer as “3DGPR”. We try to estimate the biomass of tree roots quantitatively by measuring the volume of the tree roots. We tested this system for tree roots measurement, and the expansion of tree roots with horizontal direction could be detected with a 800 MHz antenna. We excavated soil on the foot of this tree every 10 cm from 0 cm to 50 cm to validate the accuracy of the GPR estimation result. Comparing the measurement result with the excavated one, we found that the tree root whose diameter is more than 5 cm could be detected correctly. Some tree roots whose diameter is 3 cm also could be detected. Strong signals were picked up manually as signal processing. As a result, we could obtain the structure of the tree roots. In this result, we expect that the volume is supposed to be estimated within 30 percent error by using the excavated result for calibration data.