<![CDATA[Geological mapping and structural lineament extraction in active volcanic terrains with rugged topography face major constraints due to dense vegetation cover and limited terrestrial accessibility. This study aims to evaluate and compare the spectral and spatial performance of multispectral remote sensing data for geological exploration through two main aspects comparative evaluation of the Normalized Difference Vegetation Index (NDVI) between Landsat 8 OLI (30 m) and Sentinel-2A (10 m), and application of Shortwave Infrared (SWIR) band composites of Landsat 8 OLI (Bands 5, 6, and 7) for automated structural lineament extraction. The methodology encompasses Top of Atmosphere (TOA) radiometric correction, NDVI transformation, RGB 5-6-7 composite processing, and automated lineament detection using the LINE algorithm in PCI Geomatica validated against DEM Hillshade. Results indicate that Sentinel-2A (10 m) excels in delineating micro-vegetation density and reducing mixed pixel effects in steep terrains. Conversely, Landsat 8 OLI is significantly superior and more efficient for regional geological exploration owing to its seamless single-scene coverage homogeneity and the heightened sensitivity of its SWIR channels (Bands 6 and 7) toward lithological texture variations beneath vegetation cover. The RGB 5-6-7 combination clearly highlights surface roughness contrasts (rough on structural hills and fine on alluvial plains) and successfully identifies 1,248 lineament segments with a dominant West–East (W – E) trend. This structural trend represents regional faulting and fracturing controlling the hydrothermal and hydrogeological systems of Mount Lawu.]]>
