Minerals Detection and Mapping in the Southwestern Algeria Gara-Djebilet Region with a Multistage Informed NMF-Based Unmixing Approach Using Prisma Remote Sensing Hyperspectral Data

In this paper, a novel approach, based on a multistage informed spectral unmixing technique, for detecting and mapping several mineral deposits in the Gara-Djebilet region (Southwestern Algeria), is presented. The considered technique, which is related to linear spectral unmixing methods, uses an iterative informed multiplicative nonnegative matrix factorization algorithm. This technique unmixes the used PRISMA hyperspectral remote sensing data by exploiting known spectra of the considered minerals. More precisely, the originality of this work consists in applying iteratively, in two stages, the considered informed unmixing algorithm. During the first stage, abundant but irrelevant minerals, with known spectra and present in the considered region, are detected, and are then removed from the original hyperspectral data, which thus lead to the creation of new hyperspectral data to which the considered unmixing technique is applied, during the second stage, in order to detect and map other relevant minerals, with known spectra, and possibly together with unknown materials. Experiments are carried out with the considered real hyperspectral data, which cover the studied area, to assess the potential of the proposed approach. The obtained results are mainly confirmed and validated by prior knowledge of the investigated area.