Brussels image-based library of urban materials

The header file <em>UrbanSpectralLibrary_APEX_Brussels_2015_GENLIB.hdr</em> and its associated spectral library file <em>UrbanSpectralLibrary_APEX_Brussels_2015_GENLIB.sli</em> constitute a library of 1274 urban cover type spectra describing surface reflectance over the VNIR-SWIR wavelength domain. The library spectra were extracted from a 2m-resolution APEX airborne hyperspectral image of Brussels (SONIA site of BELAIR program) acquired during the summer of 2015. The source image can be downloaded from the VITO Product Distribution Portal. Endmember pixels were algorithmically selected using Iterative Spectral Distancing (see this paper for more info), and the corresponding endmember spectra were smoothed with a Gaussian filter. Note that the WGS84 latitude-longitude coordinates of the endmember pixels are included in the header file. The spectra were manually interpreted and labelled using high-resolution aerial imagery, Google Street View, online documentation and comparison to previously published urban spectral libraries (SLUM, KLUM, UCSB ...). Three sets of spectra labels are provided in this library: one for EAGLE land cover (EAGLE_LCC, consult the EAGLE website for more info), one for generalized material groupings (GENLIB_LCH_BuC_MG) and one for more detailed artificial material type (GENLIB_LCH_BuC_AMT).