1.2.3. Fiber Optic Reflectance Spectroscopy (FORS)

FORS spectral information was generated and recorded by a FieldSpect-4 ASD system, with spectra in the visible, near infrared (NIR), and short-wave infrared (SWIR) wavelengths. Spectral resolution is 3 nm for the visible and NIR regions (300–1000 nm), and 10 nm for the remaining region of the spectra (1000–2500 nm). The analysis area is about 1 cm<sup>2</sup> , and requires the probe to be in contact with the studied object. The system employs a D65 illuminant, and spectra acquisition time was set at 0.2 s. The system is routinely calibrated by an ASD Inc. certified reflectance standard (AS-02035-000CSTM-SRM-990-362).
