Table 5.
Determination accuracies of Cr concentrations based on spectral bands associated with SOM.
| Preprocessing | PLSR | PCR | SVMR | |||
|---|---|---|---|---|---|---|
| RMSE | R2 | RMSE | R2 | RMSE | R2 | |
| SG + CR | 3.61 | 0.04 | 3.67 | 0.004 | 3.28 | 0.2 |
| SG + CR + NOR | 3.48 | 0.11 | 3.5 | 0.09 | 3.33 | 0.18 |
| SG + CR + MSC | 3.61 | 0.04 | 3.65 | 0.004 | 3.32 | 0.12 |
| SG + CR + SNV | 3.61 | 0.04 | 3.67 | 0.004 | 3.27 | 0.2 |
| SG + CR + FD | 0.65 | 0.97 | 2.98 | 0.34 | 2.98 | 0.42 |
| SG + CR + NOR + FD | 3.21 | 0.24 | 3.66 | 0.008 | 3.09 | 0.31 |
| SG + CR + MSC + FD | 0.5 | 0.98 | 3.48 | 0.11 | 2.72 | 0.51 |
| SG + CR + SNV + FD | 0.53 | 0.98 | 3.02 | 0.32 | 2.65 | 0.54 |
| SG + CR + SD | 0.21 | 0.99 | 3.33 | 0.18 | 2.19 | 0.77 |
| SG + CR + NOR + SD | 3.04 | 0.32 | 3.19 | 0.25 | 3.05 | 0.35 |
| SG + CR + MSC + SD | 2.95 | 0.36 | 3.31 | 0.19 | 2.23 | 0.75 |
| SG + CR + SNV + SD | 0.51 | 0.98 | 3.32 | 0.19 | 2.2 | 0.77 |
| SG + CR + LOG | 3.61 | 0.04 | 3.67 | 0.004 | 3.32 | 0.21 |
| SG + CR + NOR + LOG | 3.39 | 0.15 | 3.5 | 0.1 | 3.13 | 0.34 |
| SG + CR + MSC + LOG | 3.61 | 0.04 | 3.67 | 0.004 | 3.33 | 0.2 |
| SG + CR + SNV + LOG | 3.62 | 0.03 | 3.66 | 0.007 | 3.47 | 0.12 |