jlima-geol/spectral-geology-copperbelt

Multi-sensor remote sensing case studies (ASTER, hyperspectral, SAR) for hydrothermal alteration mapping and structural analysis in the Central African Copperbelt (Kolwezi, Cu-Co mineralization) # Spectral Geology — Central African Copperbelt A series of remote sensing case studies applying multispectral, hyperspectral, thermal, and SAR data to geological target discrimination and hydrothermal alteration mapping over the Central African Copperbelt (Kolwezi, Zambia/DRC). ## Motivation Cu-Co mineralization in the Copperbelt is associated with hydrothermal/supergene alteration (iron oxide, clay, carbonate/chlorite) and structural controls (faults, folds) that leave distinct signatures across different parts of the electromagnetic spectrum. No single sensor captures the full picture: - **Optical (VNIR-SWIR)** discriminates alteration minerals by reflectance, but coarse band sets struggle to separate mineralogically similar phases. - **Hyperspectral** resolves this with dozens of narrow bands, enabling endmember-level mineral mapping. - **Thermal (TIR)** captures silica content and emissivity. This information the VNIR-SWIR domain misses entirely. - **SAR (microwave)** is independent of solar illumination and cloud cover, and is sensitive to structure/roughness rather than composition. This is well suited to structural lineament mapping. This series tests each spectral domain on the same study area and, eventually, integrates the results into a multi-sensor mineral favorability model. ## Projects | # | Project | Spectral domain | Status | |---|---------|------------------|--------| | 1 | `aster-copperbelt-alteration/` | Optical multispectral (ASTER VNIR-SWIR) | [x] Completed | | 2 | `hyperspectral-enmap-kolwezi/` | Hyperspectral (EnMAP/PRISMA) | [ ] Planned | | 3 | `thermal-silica-index-aster/` | Thermal infrared (ASTER TIR) | [ ] Planned | | 4 | `sar-lineaments-copperbelt/` | Microwave / structural photogeology (Sentinel-1) | [ ] Planned | | 5 | `multisensor-mineral-favorability/` | Multi-sensor synthesis | [ ] Planned | ### 1. Hydrothermal alteration mapping (ASTER) Band-ratio mapping of iron oxide, Al-OH/clay, and carbonate/dolomite alteration over AS …