Figure 3.
Soil pretreatment under different spectral indices (northwest China): (a) multiplicative scatter correction (MSC), (b) mean centering (MC), (c) moving average (MA), (d) Savitzky–Golay (SG), (e) first derivative after Savitzky–Golay (SG-FD), (f) second derivative after Savitzky–Golay (SG-SD), (g) first derivative (FD), (h) second derivative (SD), (i) continuum removal (CR), and (j) inverse-log reflectance (Log(1/R)).