GMODL: An Indonesian MATLAB-based ground-penetrating radar data modeling and processing software

Abstract

Ground-penetrating radar (GPR) data modeling and processing is crucial to near-surface geophysics. Its use in geohazard mitigation, construction, shallow hydrocarbon contamination, and other shallow subsurface detection is undeniable due to its high-resolution imaging. GPR software (MATGPR) that we used currently requires access to MATLAB which not everybody can use because of its licensing prices. Thus, we developed this program (GMODL) that uses finite-difference time-domain (FDTD) and split-step Fourier algorithms. To test the software, we created synthetic models. The synthetic model used for the testing is a river model for flood mitigation that consists of a layer of freshwater with ρ = 20 Ωm, k = 81 and μ_r = 1 of depth 5 m, two layers of sandstone with ρ = 850 Ωm, k = 2.5 and μ_r = 1 of total depth 4 m, and a layer of claystone with ρ = 120 Ωm, k = 11 and μ_r = 1 of depth 1 m. The GPR antenna frequency is set to 250 MHz. The testing algorithm of GMODL shows that it can create a synthetic radargram for the river model. The boundary layers are obvious to identify. Also, the freshwater thickness can be determined from the radargram.