Brussels image-based library of urban materials

<p>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.</p> <p>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 <a href="https://www.vito-eodata.be">VITO Product Distribution Portal</a>.</p> <p>Endmember pixels were algorithmically selected using Iterative Spectral Distancing (see <a href="https://doi.org/10.1109/IGARSS47720.2021.9555079">this paper</a> 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.</p> <p>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 <a href="https://land.copernicus.eu/eagle">EAGLE website</a> for more info), one for generalized material groupings (GENLIB_LCH_BuC_MG) and one for more detailed artificial material type (GENLIB_LCH_BuC_AMT).</p>