{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,9]],"date-time":"2026-07-09T04:22:01Z","timestamp":1783570921539,"version":"3.55.0"},"reference-count":55,"publisher":"MDPI AG","issue":"8","license":[{"start":{"date-parts":[[2014,7,25]],"date-time":"2014-07-25T00:00:00Z","timestamp":1406246400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/3.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Remote sensing analysis is a crucial tool for monitoring the extent of mine waste surfaces and their mineralogy in countries with a long mining history, such as South Africa, where gold and platinum have been produced for over 90 years. These mine waste sites have the potential to contain problematic trace element species (e.g., U, Pb, Cr). In our research, we aim to combine the mapping and monitoring capacities of multispectral and hyperspectral spaceborne sensors. This is done to assess the potential of existing multispectral and hyperspectral spaceborne sensors (OLI and Hyperion) and future missions, such as Sentinel-2 and EnMAP (Environmental Mapping and Analysis Program), for mapping the spatial extent of these mine waste surfaces. For this task we propose a new index, termed the iron feature depth (IFD), derived from Landsat-8 OLI data to map the 900-nm absorption feature as a potential proxy for monitoring the spatial extent of mine waste. OLI was chosen, because it represents the most suitable sensor to map the IFD over large areas in a multi-temporal manner due to its spectral band layout; its (183 km \u00d7 170 km) scene size and its revisiting time of 16 days. The IFD is in good agreement with primary and secondary iron-bearing minerals mapped by the Material Identification and Characterization Algorithm (MICA) from EO-1 Hyperion data and illustrates that a combination of hyperspectral data (EnMAP) for mineral identification with multispectral data (Sentinel-2) for repetitive area-wide mapping and monitoring of the IFD as mine waste proxy is a promising application for future spaceborne sensors. A maximum, absolute model error is used to assess the ability of existing and future multispectral sensors to characterize mine waste via its 900-nm iron absorption feature. The following sensor-signal similarity ranking can be established for spectra from gold mining material: EnMAP 100% similarity to the reference, ALI 97.5%, Sentinel-2 97%, OLI and ASTER 95% and ETM+ 91% similarity.<\/jats:p>","DOI":"10.3390\/rs6086790","type":"journal-article","created":{"date-parts":[[2014,7,25]],"date-time":"2014-07-25T10:54:02Z","timestamp":1406285642000},"page":"6790-6816","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":75,"title":["Spaceborne Mine Waste Mineralogy Monitoring in South Africa, Applications for Modern Push-Broom Missions: Hyperion\/OLI and EnMAP\/Sentinel-2"],"prefix":"10.3390","volume":"6","author":[{"given":"Christian","family":"Mielke","sequence":"first","affiliation":[{"name":"Helmholtz Centre Potsdam, German Research Centre for Geosciences, Telegrafenberg,  14473 Potsdam, Germany"},{"name":"Institut f\u00fcr Erd- und Umweltwissenschaften, Universit\u04d3t Potsdam, 14476 Potsdam, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Nina","family":"Boesche","sequence":"additional","affiliation":[{"name":"Helmholtz Centre Potsdam, German Research Centre for Geosciences, Telegrafenberg,  14473 Potsdam, Germany"},{"name":"Institut f\u00fcr Erd- und Umweltwissenschaften, Universit\u04d3t Potsdam, 14476 Potsdam, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christian","family":"Rogass","sequence":"additional","affiliation":[{"name":"Helmholtz Centre Potsdam, German Research Centre for Geosciences, Telegrafenberg,  14473 Potsdam, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hermann","family":"Kaufmann","sequence":"additional","affiliation":[{"name":"Helmholtz Centre Potsdam, German Research Centre for Geosciences, Telegrafenberg,  14473 Potsdam, Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Christoph","family":"Gauert","sequence":"additional","affiliation":[{"name":"Department of Geology, University of the Free State (UFS), Bloemfontein 9300, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Maarten","family":"De Wit","sequence":"additional","affiliation":[{"name":"Africa Earth Observatory Network (AEON), Nelson Mandela Metropolitain University, Summerstrand, Port Elizabeth 6031, South Africa"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2014,7,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"47","DOI":"10.1021\/es990046w","article-title":"Using imaging spectroscopy to map acidic mine waste","volume":"34","author":"Swayze","year":"2000","journal-title":"Environ. Sci. Technol"},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"453","DOI":"10.1016\/j.chemgeo.2004.06.045","article-title":"Characterization of waste rock associated with acid drainage at the Penn Mine, California, by ground-based visible to short-wave infrared reflectance spectroscopy assisted by digital mapping","volume":"215","author":"Montero","year":"2005","journal-title":"Chem. Geol"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1957","DOI":"10.1007\/s12665-011-1422-0","article-title":"Pyrite mine waste and water mapping using Hymap and Hyperion hyperspectral data","volume":"66","author":"Riaza","year":"2012","journal-title":"Environ. Earth Sci"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"3222","DOI":"10.1016\/j.rse.2008.03.017","article-title":"Mapping of heavy metal pollution in stream sediments using combined geochemistry, field spectroscopy, and hyperspectral remote sensing: A case study of the Rodalquilar mining area, SE Spain","volume":"112","author":"Choe","year":"2008","journal-title":"Remote Sens. Environ"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"64","DOI":"10.1117\/12.453691","article-title":"Monitoring of environmental changes caused by hard-coal mining","volume":"4545","author":"Fischer","year":"2002","journal-title":"Proc. SPIE"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"220","DOI":"10.1080\/17445647.2012.705544","article-title":"Application of high altitude and ground-based spectroradiometry to mapping hazardous low-pH material derived from the Sokolov open-pit mine","volume":"8","author":"Chevrel","year":"2012","journal-title":"J. Maps"},{"key":"ref_7","first-page":"28","article-title":"Using multiple spectral feature analysis for quantitative pH mapping in a mining environment","volume":"28","year":"2014","journal-title":"Int. J. Appl. Earth Obs. Geoinf"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"3937","DOI":"10.1080\/01431160801891788","article-title":"Spectral unmixing of airborne hyperspectral data for baseline mapping of mine tailings areas","volume":"29","author":"Richter","year":"2008","journal-title":"Int. J. Remote Sens"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Debba, P., Carranza, E.J.M., Stein, A., and van der Meer, F.D. (2009, January 21\u201327). Optimum Sampling Scheme for Characterization of Mine Tailings. Capte Town, South Africa.","DOI":"10.1109\/IGARSS.2009.5417522"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1016\/j.isprsjprs.2012.09.014","article-title":"Mapping the distribution of ferric iron minerals on a vertical mine face using derivative analysis of hyperspectral imagery (430\u2013970 nm)","volume":"75","author":"Murphy","year":"2013","journal-title":"ISPRS J. Photogramm. Remote Sens"},{"key":"ref_11","unstructured":"McCarthy, T.S., Steyl, G., Maree, J., Zhao, B., Ramontja, T., Coetzee, H., Hobbs, P.J., Burgess, J.E., Thomas, A., and Keet, M. (2010). Mine Water Management in the Witwatersrand Gold Fields with Special Emphasis on Acid Mine Drainage, Department of Water Affairs, South Africa."},{"key":"ref_12","unstructured":"Harrison, S., Broadhurst, J., van Hille, R., Oyekola, O., Hesketh, B.C., and Opitz, A.A. (2010). A Systematic Approach to Sulphidic Waste Rock and Tailings Management to Minimise Acid Rock Drainage Formation: Report to the Water Research Commission, Water Research Commission."},{"key":"ref_13","unstructured":"Coetzee, H. (2013, January 10\u201311). Acid Mine Drainage in South Africa: Applications of EO Products and the EO-Miners Experience. Versailles, France."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1149","DOI":"10.1109\/TGRS.2003.815999","article-title":"Overview of the Earth Observing One (EO-1) mission","volume":"41","author":"Ungar","year":"2003","journal-title":"IEEE Trans. Geosci. Remote Sens"},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"1180","DOI":"10.1109\/TGRS.2003.813210","article-title":"Cross comparison of EO-1 sensors and other Earth resources sensors to Landsat-7 ETM+ using Railroad Valley Playa","volume":"41","author":"Thome","year":"2003","journal-title":"IEEE Trans. Geosci. Remote Sens"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"11","DOI":"10.1016\/j.rse.2011.08.026","article-title":"The next Landsat satellite: The Landsat Data Continuity Mission","volume":"122","author":"Irons","year":"2012","journal-title":"Remote Sens. Environ"},{"key":"ref_17","doi-asserted-by":"crossref","unstructured":"Kaufmann, H., Segl, K., Guanter, L., Hofer, S., Foerster, K.P., Stuffler, T., Mueller, A., Richter, R., Bach, H., and Hostert, P. (2008, January 7\u201311). Environmental Mapping and Analysis Program (EnMAP)\u2014Recent Advances and Status. Boston, MA, USA.","DOI":"10.1109\/IGARSS.2008.4779668"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"25","DOI":"10.1016\/j.rse.2011.11.026","article-title":"Sentinel-2: ESA\u2019s Optical High-Resolution Mission for GMES Operational Services","volume":"120","author":"Drusch","year":"2012","journal-title":"Remote Sens. Environ"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"7967","DOI":"10.1029\/JB086iB09p07967","article-title":"Near-infrared spectral reflectance of mineral mixtures: Systematic combinations of pyroxenes, olivine, and iron oxides","volume":"86","author":"Singer","year":"1981","journal-title":"J. Geophys. Res.: Solid Earth"},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"2843","DOI":"10.1109\/TGRS.2013.2266672","article-title":"Consistency of measurements of wavelength position from hyperspectral imagery: Use of the ferric iron crystal field absorption at $sim$900 nm as an indicator of mineralogy","volume":"52","author":"Murphy","year":"2014","journal-title":"IEEE Trans. Geosci. Remote Sens"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1441","DOI":"10.1029\/JB092iB02p01441","article-title":"Discrimination of iron alteration minerals in visible and near-infrared reflectance data","volume":"92","author":"Townsend","year":"1987","journal-title":"J. Geophys. Res.: Solid Earth"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"1613","DOI":"10.2113\/gsecongeo.74.7.1613","article-title":"Spectra of altered rocks in the visible and near infrared","volume":"74","author":"Hunt","year":"1979","journal-title":"Econ. Geol"},{"key":"ref_23","first-page":"17","article-title":"Recent developments concerning the geological history and genesis of the Witwatersrand gold deposits, South Africa","volume":"9","author":"Goldfarb","year":"2002","journal-title":"Integrated Methods for Discovery: Global Exploration in the Twenty-First Century"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1144\/GSL.SP.2005.248.01.02","article-title":"Gold mineralization within the Witwatersrand Basin, South Africa: evidence for a modified placer origin, and the role of the Vredefort impact event","volume":"248","author":"Hayward","year":"2005","journal-title":"Geol. Soc. Lond. Spec. Publ"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"465","DOI":"10.2113\/gsecongeo.103.3.465","article-title":"Precise age of the Platiniferous Merensky Reef, bushveld complex, South Africa, by the U-Pb Zircon Chemical Abrasion ID-TIMS technique","volume":"103","author":"Scoates","year":"2008","journal-title":"Econ. Geol"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"495","DOI":"10.1093\/petrology\/egl069","article-title":"Origin of the UG2 chromitite layer, Bushveld Complex","volume":"48","author":"Mondal","year":"2007","journal-title":"J. Petrol"},{"key":"ref_27","first-page":"1","article-title":"The flow of slurry from a breached tailings dam","volume":"81","author":"Blight","year":"1981","journal-title":"J. South Afr. Inst. Min. Metall"},{"key":"ref_28","first-page":"707","article-title":"Retreatment of residues and waste rock","volume":"2","author":"Bosch","year":"1987","journal-title":"Extr. Metall. Gold South Afr"},{"key":"ref_29","unstructured":"Mielke, C., Fuchs, Y., Rogass\u00b8, C., Segl, K., Pustlauck, F., Blumenstein, O., Kaufmann, H., and de Wit, M. (2012, January 24\u201325). The Potential of Spectroscopy to Monitor Mine Waste and Acid Mine Drainage in South Africa. Mykonos Island, Greece."},{"key":"ref_30","first-page":"112","article-title":"Multi- and hyperspectral geologic remote sensing: A review","volume":"14","author":"Hecker","year":"2012","journal-title":"Int. J. Appl. Earth Obs. Geoinf"},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1016\/S0169-1368(99)00007-4","article-title":"Remote sensing for mineral exploration","volume":"14","author":"Sabins","year":"1999","journal-title":"Ore Geol. Rev"},{"key":"ref_32","unstructured":"Heinrich, V., Krauss, G., Goetze, C., and Sandow, C. IDB\u2014Index DataBase. Available online: http:\/\/www.indexdatabase.de\/."},{"key":"ref_33","unstructured":"Richter, R., and Schl\u00e4pfer, D. (2012). Atmospheric\/Topographic Correction for Satellite Imagery, ReSe Applications Schl\u00e4pfer. ATCOR-2\/3 User Guide Version;."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"600","DOI":"10.1109\/TIP.2003.819861","article-title":"Image quality assessment: From error visibility to structural similarity","volume":"13","author":"Wang","year":"2004","journal-title":"IEEE Trans. Image Process"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"e453","DOI":"10.7717\/peerj.453","article-title":"scikit-image: Image processing in Python","volume":"2","author":"Schoenberger","year":"2014","journal-title":"PeerJ"},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1029\/2002JE001847","article-title":"Imaging spectroscopy: Earth and planetary remote sensing with the USGS Tetracorder and expert systems","volume":"108","author":"Clark","year":"2003","journal-title":"J. Geophys. Res.: Planets"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"350","DOI":"10.1016\/S0034-4257(02)00127-X","article-title":"Lithologic mapping in the Mountain Pass, California area using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data","volume":"84","author":"Rowan","year":"2003","journal-title":"Remote Sens. Environ"},{"key":"ref_38","unstructured":"Kalinowski, A., and Oliver, S. (2004). ASTER Mineral Index Processing Manual, Australian Government Publication; Remote Sensing Applications, Geoscience Australia."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"235","DOI":"10.1016\/S0301-9268(03)00070-6","article-title":"Geological control of massive sulfide mineralization in the Neoproterozoic Wadi Bidah shear zone, southwestern Saudi Arabia, inferences from orbital remote sensing and field studies","volume":"123","author":"Volesky","year":"2003","journal-title":"Precambrian Res"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1080\/02757259509532298","article-title":"A review of vegetation indices","volume":"13","author":"Bannari","year":"1995","journal-title":"Remote Sens. Rev"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"1246","DOI":"10.1109\/TGRS.2003.813206","article-title":"Preprocessing EO-1 Hyperion hyperspectral data to support the application of agricultural indexes","volume":"41","author":"Datt","year":"2003","journal-title":"IEEE Trans. Geosci. Remote Sens"},{"key":"ref_42","doi-asserted-by":"crossref","unstructured":"Staenz, K., Neville, R.A., Clavette, S., Landry, R., White, H.P., and Hitchcock, R. (2002, January 24\u201328). Retrieval of Surface Reflectance from Hyperion Radiance Data. Toronto, ON, Canada.","DOI":"10.4095\/219887"},{"key":"ref_43","doi-asserted-by":"crossref","unstructured":"Kokaly, R.F. (2012). Spectroscopic remote sensing for material identification, vegetation characterization, and mapping. Proc. SPIE, 8390.","DOI":"10.1117\/12.919121"},{"key":"ref_44","unstructured":"Rabe, A., Jakimov, B., Held, M., van der Linden, S., and Hostert, P. EnMAP-Box. Available online: http:\/\/www.enmap.org\/?q=box_download."},{"key":"ref_45","unstructured":"Baarstad, I., L\u00f8ke, T., and Kaspersen, P. (2005, January 26\u201329). ASI\u2014A New Airborne Hyperspectral Imager. Warsaw, Poland."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"1045","DOI":"10.1016\/S0098-3004(03)00104-3","article-title":"An IDL\/ENVI implementation of the FFT-based algorithm for automatic image registration","volume":"29","author":"Xie","year":"2003","journal-title":"Comput. Geosci"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"847","DOI":"10.1080\/014311600210326","article-title":"The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER): Data products for the high spatial resolution imager on NASA\u2019s Terra platform","volume":"21","author":"Abrams","year":"2000","journal-title":"Int. J. Remote Sens"},{"key":"ref_48","unstructured":"Boggs, T. Spectral Python (SPy)\u2014Spectral Python 0.14 Documentation. Available online: http:\/\/www.spectralpython.net\/."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"522","DOI":"10.1109\/JSTARS.2012.2188994","article-title":"EeteS\u2014The EnMAP end-to-end simulation tool","volume":"5","author":"Segl","year":"2012","journal-title":"IEEE J. Sel. Top. Appl. Earth Obs. Remote Sens"},{"key":"ref_50","unstructured":"Keef, J.L. (2008). Hyper-spectral Sensor Calibration Extrapolated from Multi-Spectral Measurements, Ph.D. Thesis, University of Arizona, Tucson, AZ, USA."},{"key":"ref_51","unstructured":"(2007). USGS Digital Spectral Library splib06a, U.S. Geological Survey Data Series; Digital Data Series 231; U.S. Geological Survey."},{"key":"ref_52","unstructured":"Anthony, J.W., Bideaux, R.A., Bladh, K.W., and Nichols, M.C. (2004). Handbook of Mineralogy, Mineralogical Society of America."},{"key":"ref_53","unstructured":"Reid, L. Mineralogy and Geochemistry of Mine Dump, Tailings Site and Pipeline Spillage Samples from Impala Platinum Mine in Rustenburg. B.Sc. Thesis, Geology Department, University of the Free State, Bloemfontein, South Africa, 2012; unpublished."},{"key":"ref_54","unstructured":"Makhado, T.C. Mineralogy and Geochemistry of Mine Dump, Tailings Site Samples from the Stilfontein Gold Mining Site. B.Sc. Thesis, Geology Department, University of the Free State, Bloemfontein, South Africa, 2012; unpublished."},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"1969","DOI":"10.1080\/014311698215090","article-title":"Role of organic matter in obliterating the effects of iron on spectral reflectance and colour of Brazilian tropical soils","volume":"19","author":"Galvao","year":"1998","journal-title":"Int. J. Remote Sens"}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/6\/8\/6790\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T21:14:04Z","timestamp":1760217244000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/6\/8\/6790"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2014,7,25]]},"references-count":55,"journal-issue":{"issue":"8","published-online":{"date-parts":[[2014,8]]}},"alternative-id":["rs6086790"],"URL":"https:\/\/doi.org\/10.3390\/rs6086790","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2014,7,25]]}}}