{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,4,17]],"date-time":"2026-04-17T04:27:35Z","timestamp":1776400055982,"version":"3.51.2"},"reference-count":46,"publisher":"MDPI AG","issue":"18","license":[{"start":{"date-parts":[[2019,9,15]],"date-time":"2019-09-15T00:00:00Z","timestamp":1568505600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Graduate School for Climate and Environment (GRACE)","award":["GRACE Scholarship STIP 2016-17"],"award-info":[{"award-number":["GRACE Scholarship STIP 2016-17"]}]},{"DOI":"10.13039\/501100001655","name":"Deutscher Akademischer Austauschdienst","doi-asserted-by":"publisher","award":["RISE Germany 2018"],"award-info":[{"award-number":["RISE Germany 2018"]}],"id":[{"id":"10.13039\/501100001655","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Remote Sensing"],"abstract":"<jats:p>Knowledge about the existing materials in urban areas has, in recent times, increased in importance. With the use of imaging spectroscopy and hyperspectral remote sensing techniques, it is possible to measure and collect the spectra of urban materials. Most spectral libraries consist of either spectra acquired indoors in a controlled lab environment or of spectra from afar using airborne systems accompanied with in situ measurements. Furthermore, most publicly available spectral libraries have, so far, not focused on facade materials but on roofing materials, roads, and pavements. In this study, we present an urban spectral library consisting of collected in situ material spectra with imaging spectroscopy techniques in the visible and near-infrared (VNIR) and short-wave infrared (SWIR) spectral range, with particular focus on facade materials and material variation. The spectral library consists of building materials, such as facade and roofing materials, in addition to surrounding ground material, but with a focus on facades. This novelty is beneficial to the community as there is a shift to oblique-viewed Unmanned Aerial Vehicle (UAV)-based remote sensing and thus, there is a need for new types of spectral libraries. The post-processing consists partly of an intra-set solar irradiance correction and recalculation of reference spectra caused by signal clipping. Furthermore, the clustering of the acquired spectra was performed and evaluated using spectral measures, including Spectral Angle and a modified Spectral Gradient Angle. To confirm and compare the material classes, we used samples from publicly available spectral libraries. The final material classification scheme is based on a hierarchy with subclasses, which enables a spectral library with a larger material variation and offers the possibility to perform a more refined material analysis. The analysis reveals that the color and the surface structure, texture or coating of a material plays a significantly larger role than what has been presented so far. The samples and their corresponding detailed metadata can be found in the Karlsruhe Library of Urban Materials (KLUM) archive.<\/jats:p>","DOI":"10.3390\/rs11182149","type":"journal-article","created":{"date-parts":[[2019,9,16]],"date-time":"2019-09-16T03:17:57Z","timestamp":1568603877000},"page":"2149","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":29,"title":["KLUM: An Urban VNIR and SWIR Spectral Library Consisting of Building Materials"],"prefix":"10.3390","volume":"11","author":[{"given":"Rebecca","family":"Ilehag","sequence":"first","affiliation":[{"name":"Institute of Photogrammetry and Remote Sensing (IPF), Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany"}]},{"given":"Andreas","family":"Schenk","sequence":"additional","affiliation":[{"name":"Institute of Photogrammetry and Remote Sensing (IPF), Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany"}]},{"given":"Yilin","family":"Huang","sequence":"additional","affiliation":[{"name":"Faculty of Applied Science and Engineering, University of Toronto, Toronto, ON M5S 1A4, Canada"}]},{"given":"Stefan","family":"Hinz","sequence":"additional","affiliation":[{"name":"Institute of Photogrammetry and Remote Sensing (IPF), Karlsruhe Institute of Technology (KIT), 76131 Karlsruhe, Germany"}]}],"member":"1968","published-online":{"date-parts":[[2019,9,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Kolbe, T.H. (2009). Representing and exchanging 3D city models with CityGML. 3D Geo-Information Sciences, Springer.","DOI":"10.1007\/978-3-540-87395-2_2"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Nouvel, R., Bahu, J.M., Kaden, R., Kaempf, J., Cipriano, P., Lauster, M., H\u00e4fele, K.H., Munoz, E., Tournaire, O., and Casper, E. (2015, January 7\u20139). Development of the CityGML application domain extension energy for urban energy simulation. Proceedings of the Building Simulation 2015\u201414th Conference of the International Building Performance Simulation Association, Hyderabad, India.","DOI":"10.26868\/25222708.2015.2863"},{"key":"ref_3","unstructured":"Kaden, R., and Kolbe, T.H. (2013, January 27\u201329). City-wide total energy demand estimation of buildings using semantic 3D city models and statistical data. Proceedings of the 8th International 3D GeoInfo Conference, Istanbul, Turkey."},{"key":"ref_4","doi-asserted-by":"crossref","unstructured":"Kottler, B., Burkard, E., Bulatov, D., and Harak\u00e9, L. (2019, January 25\u201327). Physically-Based Thermal Simulation of Large Scenes for Infrared Imaging. Proceedings of the 14th International Conference on Compute Graphics Theory and Applications, Prague, Czech Republic.","DOI":"10.5220\/0007351400002108"},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"11345","DOI":"10.1364\/OE.24.011345","article-title":"Semi-automated infrared simulation on real urban scenes based on multi-view images","volume":"24","author":"Xiong","year":"2016","journal-title":"Opt. Express"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"346","DOI":"10.1016\/j.buildenv.2015.09.019","article-title":"Exploring the effect of neighboring land cover pattern on land surface temperature of central building objects","volume":"95","author":"Feng","year":"2016","journal-title":"Build. Environ."},{"key":"ref_7","first-page":"1","article-title":"The energetic basis of the urban heat island","volume":"108","author":"Oke","year":"1982","journal-title":"Q. J. R. Meteorol. Soc."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"527","DOI":"10.1016\/j.scitotenv.2016.06.119","article-title":"Heat waves and urban heat islands in Europe: A review of relevant drivers","volume":"569","author":"Ward","year":"2016","journal-title":"Sci. Total Environ."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"217","DOI":"10.5194\/isprs-archives-XLII-1-217-2018","article-title":"Classification and representation of commonly used roofing material using multisensorial aerial data","volume":"42","author":"Ilehag","year":"2018","journal-title":"Int. Arch. Photogramm. Remote Sens. Spat. Inf. Sci."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"3085","DOI":"10.1016\/j.solener.2010.12.023","article-title":"Using advanced cool materials in the urban built environment to mitigate heat islands and improve thermal comfort conditions","volume":"85","author":"Santamouris","year":"2011","journal-title":"Sol. Energy"},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2119","DOI":"10.1016\/j.envpol.2011.03.007","article-title":"Positive effects of vegetation: Urban heat island and green roofs","volume":"159","author":"Susca","year":"2011","journal-title":"Environ. Pollut."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"326","DOI":"10.1016\/j.uclim.2017.02.002","article-title":"Using reflective pavements to mitigate urban heat island in warm climates-Results from a large scale urban mitigation project","volume":"24","author":"Kyriakodis","year":"2018","journal-title":"Urban Clim."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"145","DOI":"10.5194\/isprs-archives-XLII-2-W6-145-2017","article-title":"Concept for classifying facade elements based on material, geometry and thermal radiation using multimodal UAV remote sensing","volume":"42","author":"Ilehag","year":"2017","journal-title":"Int. Arch. Photogramm. Remote Sens. Spat. Inf. Sci."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"29","DOI":"10.1016\/j.enbuild.2013.05.040","article-title":"Image-based thermographic modeling for assessing energy efficiency of buildings fa\u00e7ades","volume":"65","year":"2013","journal-title":"Energy Build."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"4358","DOI":"10.1016\/j.apenergy.2011.05.014","article-title":"Application of infrared thermography for the determination of the overall heat transfer coefficient (U-Value) in building envelopes","volume":"88","author":"Fokaides","year":"2011","journal-title":"Appl. Energy"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"5","DOI":"10.1023\/A:1010933404324","article-title":"Random forests","volume":"45","author":"Breiman","year":"2001","journal-title":"Mach. Learn."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"273","DOI":"10.1007\/BF00994018","article-title":"Support-vector networks","volume":"20","author":"Cortes","year":"1995","journal-title":"Mach. Learn."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"1712","DOI":"10.1016\/j.rse.2009.03.018","article-title":"Hierarchical multiple endmember spectral mixture analysis (MESMA) of hyperspectral imagery for urban environments","volume":"113","author":"Franke","year":"2009","journal-title":"Remote Sens. Environ."},{"key":"ref_19","first-page":"1","article-title":"Imaging spectroscopy of urban environments","volume":"40","author":"Okujeni","year":"2018","journal-title":"Surv. Geophys."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"44","DOI":"10.4090\/juee.2011.v5n1.044056","article-title":"Development and utilization of urban spectral library for remote sensing of urban environment","volume":"5","author":"Nasarudin","year":"2011","journal-title":"J. Urban Environ. Eng."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"711","DOI":"10.1016\/j.rse.2008.11.007","article-title":"The ASTER spectral library version 2.0","volume":"113","author":"Baldridge","year":"2009","journal-title":"Remote Sens. Environ."},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Clark, R.N., Swayze, G.A., Wise, R., Livo, K.E., Hoefen, T., Kokaly, R.F., and Sutley, S.J. (2007). USGS Digital Spectral Library Splib06a.","DOI":"10.3133\/ds231"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"537","DOI":"10.1016\/j.rse.2007.04.008","article-title":"Determination of robust spectral features for identification of urban surface materials in hyperspectral remote sensing data","volume":"111","author":"Heiden","year":"2007","journal-title":"Remote Sens. Environ."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"304","DOI":"10.1016\/j.rse.2004.02.013","article-title":"Spectrometry for urban area remote sensing-Development and analysis of a spectral library from 350 to 2400 nm","volume":"91","author":"Herold","year":"2004","journal-title":"Remote Sens. Environ."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"194","DOI":"10.1016\/j.isprsjprs.2014.05.005","article-title":"Derivation of an urban materials spectral library through emittance and reflectance spectroscopy","volume":"94","author":"Kotthaus","year":"2014","journal-title":"ISPRS J. Photogramm. Remote Sens."},{"key":"ref_26","first-page":"80","article-title":"Desirex 2008: Estudio de la isla de calor en la Ciudad de Madrid","volume":"31","author":"Sobrino","year":"2009","journal-title":"Revista de Teledetecci\u00f3n"},{"key":"ref_27","first-page":"2193","article-title":"A spectral based recognition of the urban environment using the visible and near-infrared spectral region (0.4\u20131.1 \u03bcm). A case study over Tel-Aviv, Israel","volume":"22","author":"Levin","year":"2001","journal-title":"Int. J. Remote Sens."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"46","DOI":"10.4028\/www.scientific.net\/AEF.31.46","article-title":"Analysis of Building Facade Materials Usage Pattern in Tehran","volume":"32","author":"Jalali","year":"2019","journal-title":"Adv. Eng. Forum"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1016\/j.culher.2016.11.017","article-title":"Semiautomatic detection and classification of materials in historic buildings with low-cost photogrammetric equipment","volume":"25","year":"2017","journal-title":"J. Cult. Herit."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"65","DOI":"10.5194\/isprs-archives-XLII-3-W3-65-2017","article-title":"Revisiting existing classification approaches for building materials based on hyperspectral data","volume":"42","author":"Ilehag","year":"2017","journal-title":"Int. Arch. Photogramm. Remote Sens. Spat. Inf. Sci."},{"key":"ref_31","unstructured":"Fairbarn, K.G. (2013). Visible-Near Infrared (VNIR) and Shortwave Infrared (SWIR) Spectral Variability of Urban Materials. [Master\u2019s Thesis, Naval Postgraduate School]."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"993","DOI":"10.1080\/01431169508954459","article-title":"Examples of high resolution visible to near-infrared reflectance sand a standardized collection for remote sensing studies","volume":"16","author":"Price","year":"1995","journal-title":"Int. J. Remote Sens."},{"key":"ref_33","unstructured":"Heiden, U., Roessner, S., Segl, K., and Kaufmann, H. (2001, January 8\u20139). Analysis of spectral signatures of urban surfaces for their identification using hyperspectral HyMap data. Proceedings of the IEEE\/ISPRS Joint Workshop on Remote Sensing and Data Fusion over Urban Areas (Cat. No. 01EX482), Rome, Italy."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"4327","DOI":"10.1364\/AO.44.004327","article-title":"Spectral characteristics of asphalt road aging and deterioration: Implications for remote-sensing applications","volume":"44","author":"Herold","year":"2005","journal-title":"Appl. Opt."},{"key":"ref_35","first-page":"141","article-title":"Emissivity mapping over urban areas using a classification-based approach: Application to the Dual-use European Security IR Experiment (DESIREX)","volume":"18","author":"Sobrino","year":"2012","journal-title":"Int. J. Appl. Earth Obs. Geoinf."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Kokaly, R.F., Clark, R.N., Swayze, G.A., Livo, K.E., Hoefen, T.M., Pearson, N.C., Wise, R.A., Benzel, W.M., Lowers, H.A., and Driscoll, R.L. (2017). USGS Spectral Library Version 7: U.S. Geological Survey Data Series 1035.","DOI":"10.3133\/ds1035"},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Abel, J.S., and Smith, J.O. (1991, January 14\u201317). Restoring a clipped signal. Proceedings of the ICASSP 91: 1991 International Conference on Acoustics, Speech, and Signal Processing, Toronto, ON, Canada.","DOI":"10.1109\/ICASSP.1991.150655"},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"1552","DOI":"10.1109\/TGRS.2004.830549","article-title":"Distance metrics and band selection in hyperspectral processing with applications to material identification and spectral libraries","volume":"42","author":"Keshava","year":"2002","journal-title":"IEEE Trans. Geosci. Remote Sens."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"145","DOI":"10.1016\/0034-4257(93)90013-N","article-title":"The Spectral Image Processing System (SIPS)\u2014Interactive Visualization and Analysis of Imaging spectrometer Data","volume":"44","author":"Kruse","year":"1993","journal-title":"Remote Sens. Environ."},{"key":"ref_40","unstructured":"Chang, C.I. (2003). Hyperspectral Imaging: Techniques for Spectral Detection and Classification, Kluwer Academic\/Plenum Publishers."},{"key":"ref_41","doi-asserted-by":"crossref","unstructured":"Angelopoulou, E., Kee, S.W., and Bajcsy, R. (1999, January 20\u201327). Spectral gradients: A material descriptor invariant to geometry and incident illumination. Proceedings of the Seventh IEEE International Conference on Computer Vision, Kerkyra, Greece.","DOI":"10.1109\/ICCV.1999.790312"},{"key":"ref_42","unstructured":"Robila, S. (2005, January 7\u201311). An investigation of spectral metrics in hyperspectral image preprocessing for classification. In Proceeding of the Geospatial Goes Global: From Your Neighborhood to the Whole Planet, ASPRS Annual Conference, Baltimore, MD, USA."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"129","DOI":"10.1109\/TIT.1982.1056489","article-title":"Least Squares Quantization in PCM","volume":"28","author":"Lloyd","year":"1982","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"559","DOI":"10.1080\/14786440109462720","article-title":"On lines and planes of closest fit to systems of points in space","volume":"2","author":"Pearson","year":"1901","journal-title":"Lond. Edinb. Dublin Philos. Mag. J. Sci."},{"key":"ref_45","first-page":"2579","article-title":"Visualizing data using t-SNE","volume":"9","author":"Hinton","year":"2008","journal-title":"J. Mach. Learn. Res."},{"key":"ref_46","first-page":"33","article-title":"Spectral Band Selection for Urban Material Classification Using Hyperspectral Libraries","volume":"3","author":"Chehata","year":"2016","journal-title":"ISPRS Ann. Photogramm. Remote Sens. Spat. Inf. Sci."}],"container-title":["Remote Sensing"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2072-4292\/11\/18\/2149\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T13:20:25Z","timestamp":1760188825000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2072-4292\/11\/18\/2149"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2019,9,15]]},"references-count":46,"journal-issue":{"issue":"18","published-online":{"date-parts":[[2019,9]]}},"alternative-id":["rs11182149"],"URL":"https:\/\/doi.org\/10.3390\/rs11182149","relation":{},"ISSN":["2072-4292"],"issn-type":[{"value":"2072-4292","type":"electronic"}],"subject":[],"published":{"date-parts":[[2019,9,15]]}}}