Urban material ground truth data for the 2015 APEX hyperspectral image of Brussels

This dataset entails a spectral library file (.sli file with matching .hdr text file) with 1350 georeferenced and labeled spectra derived from the 2m resolution airborne hyperspectral APEX image of Brussels (Belgium) that was acquired during the summer of 2015. The labeled spectra included in this dataset describe level 2A surface reflectance profiles ranging between 450 and 2431 nm. The original APEX image files can be downloaded via the Belair website, and the preprocessing performed on this image data is explained in Sterckx et al. (2016) and Vreys et al. (2016). See the "Related works" section of this data publication.

The main purpose of this dataset is to provide Ground Truth (GT) data for remote sensing-based mapping experiments with a generic urban spectral library, performed in the frame of the GENLIB research project. The content of this dataset hence focuses on the optical reflectance/absorption behaviour of urban surface materials and their variations.

The spectra included in this dataset were manually sampled from the above mentioned APEX image and labeled using ancillary reference data (very high-resolution aerial imagery, Google Street View, LiDAR ...), already published urban spectral libraries, terrain knowledge and some field work. The header of the spectral library contains the various labels that were added to these spectra. These labels cover:

EAGLE Land Cover Component (LCC) from the EAGLE matrix version 3.1. Visit the website of the EAGLE framework for more information.

Material Groups (MG).

Artificial Material Types (AMT).

Artificial Material Coating or Fabrication (AMCF).

Artificial Material Forms (AMF).

Latitude (degrees, WGS84).

Longitude (degrees, WGS84).

The value domains of these spectrum attributes are described in the look-up table included as a CSV-file in this data publication.

While considerable efforts have been made to safeguard the accuracy of these data, they are published as is, without any warranty or support. Use at your own discretion.