Characterization of the rice canopy infested with brown spot disease using field hyperspectral data

Based on the field hyperspectral data from the analytical spectral devices (ASD) spectrometer, we characterized the spectral properties of rice canopies infested with brown spot disease and selected spectral regions and bands sensitive to four severity degrees (severe, moderate, light, and healthy). The results show that the curves’ variation on the original and the first- and second-order derivative curves are greatly different, but the spectral difference in the near-infrared region is the most obvious for each level. Specifically, the peaks are located at 822, 738, and 793 nm, while the valleys are located at 402, 570, and 753 nm, respectively. The sensitive regions are between 430–520, 530–550, and 650–710 nm, and the bands are 498, 539, and 673 nm in the sensitivity analysis, while they are in the ranges of 401–530, 550–730 as well as at 498 nm and 678 nm in the continuum removal.