Fractal-Constrained Crosshole/Borehole-to-Surface Full Waveform Inversion for Hydrogeological Applications Using Ground-Penetrating Radar

Iraklis Giannakis, Antonios Giannopoulos, Craig Warren, Anastasia Sofroniou

Research output: Contribution to journalArticlepeer-review

Abstract / Description of output

Full waveform inversion (FWI) is considered one of the most promising interpretation tools for hydro-geological applications using ground-penetrating radar. However, FWI has had limited practical uptake for several reasons: large computational requirements; an inability to reconstruct loss mechanisms of soil; and the need for a good initial starting model. We aim to address these issues via a novel FWI subject to a fractallycorrelated distribution of water. Initially, the dispersive properties of the soil are expressed as a function of the water fraction using a semi-empirical model. This approach means the permittivity, conductivity, and relaxation mechanisms are all correlated, and therefore sensitivity problems between the permittivity and loss mechanisms no longer affect the performance of FWI. Subsequently, the distribution of the water fraction is constrained to follow a fractal geometry. Fractal-correlated noise is then compressed using principal component analysis (PCA) in order to further reduce the number of the system’s unknowns and accelerate FWI. PCA reduces the volume and dimensions of the optimization space, and thus, initialisation is no longer necessary. Lastly, a novel measurement configuration is suggested that uses superposition with all the individual measurements in order to reduce the number of forward models that need to be executed for every iteration of FWI. These enhancements substantially reduce the computational requirements of FWI and therefore eliminate the need for high-performance computers and time-consuming algorithms. The proposed scheme has been successfully tested with several numerical case-studies, which indicate the potential of this approach to become a commerciallyappealing interpretation tool for hydro-geology.
Original languageEnglish
Article number5901110
Pages (from-to)1-10
Number of pages10
JournalIEEE Transactions on Geoscience and Remote Sensing
Early online date9 Feb 2021
Publication statusPublished - 2022

Keywords / Materials (for Non-textual outputs)

  • finite-difference time-domain (FDTD)
  • fractals
  • full-waveform inversion (FWI)
  • ground-penetrating radar (GPR)
  • hydrogeology
  • Principal component analysis (PCA)


Dive into the research topics of 'Fractal-Constrained Crosshole/Borehole-to-Surface Full Waveform Inversion for Hydrogeological Applications Using Ground-Penetrating Radar'. Together they form a unique fingerprint.

Cite this