*3.3. Separability of Training Data*

The mean values for training set and plot samples for *G*1*T*<sup>3</sup> and *G*2*T*<sup>3</sup> in blue vs. green and red vs. infrared band combinations were shown in Figure 3.

The samples of the VUs formed clusters which partially overlap. In particular, the spectral samples of the *Rumex obtusifolius* plants could not be well separated. In blue vs. green band combinations, the clusters were better separated than in the red vs. infrared combination. It was noticeable that the spectral values of the *Lolium perenne*-community and the *Alopecurus pratensis*-community show higher variance and mean values at *G*2*T*<sup>3</sup>

than at *G*1*T*3. Furthermore, the samples at date *G*2*T*<sup>3</sup> showed a higher reflectance in the green and infrared band than the samples at *G*1*T*3. This was caused by the prominent flower aspect of the grasses at *G*1*T*3.

**Figure 3.** Scatter plots of the samples of the dependent (◦) and independent (+) test data in blue vs. green and red vs. infrared. Colors are used as follows: **grey**: *Rumex obtusifolius* plants, **blue**: *Lolium perenne*-community, **red**: *Alopecurus pratensis*-community, **green**: *Bromus Hordeaceus*-community.
