On characterizing anisotropies of the radioactive sources from airborne gamma-ray data using bidimensional empirical mode decomposition: a case study from Algeria

Abstract The airborne gamma-ray survey aims at depicting radioelement anomalies and understanding mineralizing system of the investigated area. This study presents a new approach to exploit the spectrometric data. It is based on the decomposition of the data into several submaps, components called intrinsic mode functions using the bidimensional empirical mode decomposition method. Each component presents details at a specified scale. The empirical mode decomposition method is a versatile technique that is appropriate to handle nonlinear and nonstationary data. It enables a time-frequency analysis without the need of specifying a decomposition basis. Results, obtained from Algerian airborne gamma-ray measurements, revealed that this technique might be a powerful tool for highlighting and detecting the anomalies at different scales.