Before revision: PRI is defined by the following equation using reflectance (ρ) at 531 and 570 nm wavelength: 2 Some authors use 3 The values range from -1 to 1.
After revision: PRI is defined by the following equation using reflectance (ρ) at 531 and 570 nm wavelength: 2 Some authors use 3 The values range from –1 to 1.