Using the band ratio approach, FULL-PIXEL (SAM and SFF) and SUB-PIXEL (MF and SID) methodologies to discover areas with alteration using the Aster sensor: a case study in north westen Iran - Sivardaghi Area. Nexo Revista Científica. 2023;36(03):422-438. doi:10.5377/nexo.v36i03.16464