Estimating Depth of Influence of GPR Ground Wave in Lysimeter Experiment
摘要
To map the surface soil moisture content with GPR at an intermediate scale, the soil dielectric constant needs to be determined from the ground wave velocity. However, the depth of influence of ground wave is still not well defined. In the present study, shallow water boxes were placed at near surface (0-20 cm) inside the lysimeter to evaluate the effect on the ground wave and to compare with the theoretical depth of influence using Sperl and Van Overmeeren models. Results revealed an increase in dielectric constant with all water box measurement until 15 cm depth. While at 20 cm depth observed K value was found similar as of background soil. The theoretical prediction of GW depth using both models was found insignificant in the present study. Experimentally observed result signifies that the depth of influence of GW was similar to the quarter of the wavelength.