Spectral slope (2.1–2.5 μm) distribution as a function of the NIRS3 spatial resolution [meters]. Data are restricted to similar geometric conditions (20° < α < 30°, i < 50°, e < 50°). The data were binned in a 2D slope–resolution grid using 150 × 150 bins. The color bar corresponds to the number of points per bin. We considered only bins containing at least three points; others are considered empty. The cyan and lime solid lines represent the median and mean values from each resolution bin, respectively.