Investigating the Potential of LANDSAT 8 OLI Satellite Imagery for Geological Mapping in Namibia

Only two academic papers relating to geological remote sensing in Namibia havebeen published (Lord et al., 1996, Gomez et al., 2005) despite the complex and varied geology, cloud free atmospheres, and the almost ideal surface conditions of bedrock exposure. These two publications used moderate resolution sensors, LANDSAT MSS (1972-82, 4 - 8 spectral bands - VIS/VNIR, 80m pixels) – and ASTER ( 2000+ complex 14 spectral bands - VNIR/SWIR/TIR s 15-90m spatial resolution). There has not been any published attempt to evaluate the potential of the more readily available LANDSAT TM, ETM and OLI imagery which has a longevity originating in 1978. This poster considers the potential, via display of processed imagery, of LANDSAT 5-7 (1999-2011) and LANDSAT 8 (2013 +) satellite imagery for the purpose of spectral mapping of Namibia’s geology. It is important to note that spectral mapping is not equivalent to lithological discrimination mapping although it may be possible to draw valid lithological conclusionsfrom the spectral patterns. The capacity to perform spectral mapping or spectral stratigraphy (Prost,1994) is enhanced by the application of standard image processing techniques and the utilisation of imagery captured under different atmospheric conditions and sun’s nillumination. The latter situation has been promoted by the advent of free, frequently updated imagery distributed through the internet. Spectral mapping can enhance photogeologic mapping by sensing and displaying signals beyond the human visible spectrum.