@article{MielkeMuediPapenfussetal.2016,
  author    = {Mielke, Christian and Muedi, T. and Papenfuss, Anne and B{\"o}sche, Nina Kristine and Rogass, C. and Gauert, C. D. K. and Altenberger, Uwe and de Wit, M. J.},
  title     = {Multi- and hyperspectral spaceborne remote sensing of the Aggeneys base metal sulphide mineral deposit sites in the Lower Orange River region, South Africa},
  series = {South African Journal of Geology},
  volume    = {119},
  journal   = {South African Journal of Geology},
  publisher = {Geological Society of South Africa},
  address   = {Marshalltown},
  issn      = {1012-0750},
  doi       = {10.2113/gssajg.119.1.63},
  pages     = {63 -- 76},
  year      = {2016},
  abstract  = {New tools and algorithms for geological femote Sensing are developed and verified at test sites throughout the world in preparation of the German hyperspectral satellite Mission (EnMAP), which is an Environmental Mapping and Analysis Program. The aggeneys Cu-Pb-Zn deposit, situated in the arid north western part of South Africa, represents a unique field laboratory for testing these new tools. Here spaceborne hyperspectral data covering the Swartberg, and hyperspectral spaceborne data can be demonkrated, such as the Iron Feature Depth index (IFD), which has recently been proposed for mine waste mapping in the North West Province of South Africa and for gossan detection at Haib River in South Namibia. The work presented here explores the potential of the IFD for gossan mapping and characterization at Gamsberg and Big Syncline, from EO-1 ALI and Landsat-8 OLI data together with mineral maps from expert systems such as the United States Geological Survey (USGS) Material Identification and Characterization Algorithm (MICA), and first results from EnMAPs EnGeoMAP algorithm. Field spectroscopic measurements and field sampling were carried out to validate and calibrate the results from the expert systems and the IFD. This ground truthing is a necessary complementary step to link the results from the expert systems and the IFD to in-situ field spectroscopy. Future mineral exploration initiatives may benefit from the techniques described here, because they can significantly narrow the expensive, exploration activities such as hyperspectral airborne data, field activities and drilling, by identifying the most promising mineral anomalies in an area from the spaceborne data.},
  language  = {en}
}
@article{DaempflingMielkeKoellneretal.2022,
  author    = {D{\"a}mpfling, Helge L. C. and Mielke, Christian and Koellner, Nicole and Lorenz, Melanie and Rogass, Christian and Altenberger, Uwe and Harlov, Daniel E. and Knoper, Michael},
  title     = {Automatic element and mineral detection in thin sections using hyperspectral transmittance imaging microscopy (HyperTIM)},
  series = {European journal of mineralogy},
  volume    = {34},
  journal   = {European journal of mineralogy},
  number    = {3},
  publisher = {Copernicus},
  address   = {G{\"o}ttingen},
  issn      = {0935-1221},
  doi       = {10.5194/ejm-34-275-2022},
  pages     = {275 -- 284},
  year      = {2022},
  abstract  = {In this study we present a novel method for the automatic detection of minerals and elements using hyperspectral transmittance imaging microscopy measurements of complete thin sections (HyperTIM). This is accomplished by using a hyperspectral camera system that operates in the visible and near-infrared (VNIR) range with a specifically designed sample holder, scanning setup, and a microscope lens. We utilize this method on a monazite ore thin section from Steenkampskraal (South Africa), which we analyzed for the rare earth element (REE)-bearing mineral monazite ((Ce,Nd,La)PO4), with high concentrations of Nd. The transmittance analyses with the hyperspectral VNIR camera can be used to identify REE minerals and Nd in thin sections. We propose a three-point band depth index, the Nd feature depth index (NdFD), and its related product the Nd band depth index (NdBDI), which enables automatic mineral detection and classification for the Nd-bearing monazites in thin sections. In combination with the average concentration of the relative Nd content, it permits a destruction-free, total concentration calculation for Nd across the entire thin section.},
  language  = {en}
}