Type of reflectivity | Vegetation indices | Functional model | Regression equation | R2 | RMSE (g/L) |
---|---|---|---|---|---|
First derivative | RD | Linear | y = − 8116.9x + 13,150 | 0.71 | 1.77 |
Exponential | y = 17,860e−1.306x | 0.73 | 2.01 | ||
Quadratic | y = 3178.2x2 − 13,332x + 15,120 | 0.72 | 1.88 | ||
CIred-edge | Linear | y = − 76,288x − 66,089 | 0.80 | 0.92 | |
Exponential | y = 0.067e−12.01x | 0.78 | 0.98 | ||
Quadratic | y = − 169,389x2 − 400,646x − 221,261 | 0.80 | 0.93 | ||
NDRE | Linear | y = − 27,424x − 18,368 | 0.63 | 1.14 | |
Exponential | y = 147.75e−4.115x | 0.56 | 1.23 | ||
Quadratic | y = 126,872x2 + 207,536x + 89,944 | 0.67 | 1.18 | ||
ND705 | Linear | y = − 18,527x + 3265 | 0.82 | 1.52 | |
Exponential | y = 3707.4e−2.893x | 0.78 | 1.35 | ||
Quadratic | y = − 29,935x2 − 30,687x + 2342.8 | 0.83 | 1.69 | ||
NIR | Linear | y = − 85,125x + 10,408 | 0.39 | 1.45 | |
Exponential | y = 11,137e−12.9x | 0.35 | 1.55 | ||
Quadratic | y = − 2E + 06x2 + 47,910x + 8644.1 | 0.44 | 1.44 | ||
RI-1 dB | Linear | y = − 19,373x + 22,583 | 0.52 | 2.37 | |
Exponential | y = 78,853e−3.076x | 0.52 | 2.91 | ||
Quadratic | y = 126,872x2 + 207,536x + 89,944 | 0.59 | 2.83 | ||
Original | RD | Linear | y = − 8564.7x + 25,826 | 0.65 | 1.50 |
Exponential | y = 131,902e−1.36x | 0.65 | 1.57 | ||
Quadratic | y = − 10,788x2 + 39,287x − 26,804 | 0.67 | 1.47 | ||
CIred-edge | Linear | y = − 3415.6x + 14,222 | 0.54 | 1.69 | |
Exponential | y = 19,774e−0.516x | 0.49 | 1.81 | ||
Quadratic | y = − 357.75x2 − 1914.2x + 12,720 | 0.54 | 1.67 | ||
NDRE | Linear | y = − 28,351x + 17,684 | 0.59 | 1.70 | |
Exponential | y = 34,790e−4.394x | 0.56 | 1.81 | ||
Quadratic | y = − 202,849x2 + 124,311x − 10,381 | 0.63 | 1.60 | ||
ND705 | Linear | y = − 2745.6x + 16,233 | 0.58 | 2.38 | |
Exponential | y = 29,232e−0.441x | 0.59 | 2.41 | ||
Quadratic | y = − 35.761x2 − 2493x + 15,800 | 0.58 | 2.34 | ||
NIR | Linear | y = − 28,744x + 38,765 | 0.62 | 1.66 | |
Exponential | y = 946,939e−4.488x | 0.60 | 1.81 | ||
Quadratic | y = − 180,524x2 + 369,826x − 180,634 | 0.66 | 1.53 | ||
RI-1 dB | Linear | y = − 10,960x + 28,560 | 0.59 | 1.58 | |
Exponential | y = 199,238e−1.729x | 0.58 | 1.67 | ||
Quadratic | y = − 26,273x2 + 92,468x − 72,663 | 0.64 | 1.52 |