*2.3. Data Preprocessing*

Some spectral bands (1350 nm to 1450 nm, 1810 nm to 1940 nm and 2400 nm to 2500 nm) have been removed due to a small signal-to-noise ratio resulting from strong atmospheric absorption mainly due to the presence of water vapour. More precisely, if the atmospheric transmittance value of the U.S. Standard profile was lower than 0.8 for a given wavelength, this wavelength was not taken into account in the analyse. Thus, each measured spectrum has been smoothed using a Savitzky-Golay filter [32] for reducing the noise. Figure 2 graphs the mean spectral reflectance of each vegetation type and the atmospheric transmittance. For the sake of clarity, the standard deviation of each vegetation type is not printed on Figure 2 but can be seen in Appendix B.

**Figure 2.** Mean spectral reflectances of the 13 vegetation types and the U.S. Standard atmospheric transmittance.
