An Advanced GPR Modelling Framework: The Next Generation of gprMax

gprMax is a freely-available set of electromagnetic wave simulation tools based on the Finite-Difference Time-Domain (FDTD) numerical method. gprMax was originally written in the mid-1990s and has primarily been used to simulate Ground Penetrating Radar (GPR). Current computing resources offer the opportunity to build detailed and complex FDTD models of GPR to an extent that was not previously possible. To enable these types of simulations to be more easily realised, and also to facilitate the addition of more advanced features, significant modernisations have been made to gprMax. The original C-based code has been completely rewritten using a combination of Python and Cython programming languages. Standard and robust file formats have been chosen for geometry and field output files. New advanced modelling features have been added including: an unsplit implementation of higher order perfectly matched layers (PMLs) using a recursive integration approach; uniaxially anisotropic materials; dispersive media using multiple Debye, Drude or Lorenz expressions; improved soil modelling using a semi-empirical formulation for dielectric properties and fractals for geometric characteristics; rough surface generation; and the ability to embed complex transducers and targets.