Model 1 (top) and model 2 (bottom) considering the presence of crystalline H₂O with grain sizes of 5 and 10 μm, respectively (see Table 2 for details). In the upper part of each graphic, is plotted the observed spectrum (black) and the corresponding model (red), all normalized to 0.020 at 1.75 microns. In the bottom part is given the associated spectrum-model (red) and the noise (black) corresponding to the quadratic sum of the standard deviation of the data.