KARSTIFIED FEATURES INTERPRETATION THROUGH MACHINE LEARNING ALGORITHMS: CONVOLUTIONAL NEURAL NETWORKS APPLICATIONS TO GROUND PENETRATING RADAR IMAGES
Deep Learning; Convolutional Neural Networks; Ground Penetrating Radar
Most of recent papers that study Ground Penetrating Radar (GPR) and Machine Learning (ML) applications are applied to civil engineering, lacking studies applied to geosciences. In this context, the present work seeks to help fill this gap by studying automatic GPR interpretation with machine learning methods in the context of a karstified environment with carbonate rocks from the Irece Basin (Brazil). In the case of this work, there are two classes that represent two different expected interpretations. The first one represents a karstified feature in carbonates, while the second is anything but the karstified feature. The present work had access to eight GPR sections. From these sections, the following attributes were generated: Energy, Similarity, Instantaneous Amplitude, Instantaneous Phase, Instantaneous Frequency, Hilbert Trace, Maximum Spectral Amplitude, Quality Factor, Hilbert Trace/Energy, and Hilbert Trace/Similarity. To achieve this automatic interpretation, a state-of-art Deep Learning algorithm, named U-Net Convolutional Neural Network, commonly applied to images is used, combined with a feature selection method through Genetic Algorithms used to select the best subset of features that will impact positively the model’s performance. The obtained results show that it is possible, in fact, to generate automatic models for interpreting GPR sections using U-Net. Furthermore, by continually comparing the results using different sets of solutions, it was found that the methodology and model are robust enough and allow more than one possible solution to obtain an evaluation metric above 95% when interpreting karstified regions