Bernardino Buenaobra, Mark Manhuyod, Annie Diola, Claurice Mangle, Michelle Abarca, Benjamin Mabanta, Roland Otadoy
We report in this paper the results of spectroradiometric measurement in determination of the complete spectral signature of sample leafs with distinct and differing quality conditions by obtaining their response in the visible wavelengths (VIS), at near infrared (NIR) to the shortwave (SW) bands. Here we refer to the dynamics beyond the NIR as the extended range for the spectral response of the instrument from 1000nm to 2500nm. At these bands they indicate their relative reectance and absorption values that translates to the quantification and indications of health of cell structure, water content, leaf biochemical, protein lignin, and celluse as well of the presence of nitrogen content. We obtained the numerical result by simple graphical analysis from the spectral plots at certain wavelengths for the vegetation index of interest.The reectance values from 1510nm will yield the Normalized Difference Nitrogen Index (NDNI) where nitrogen concentration and overall biomass in foliage could be indicated. At 1754nm the Normalized Difference Lignin Index (NDLI) estimate the relative amounts of lignin contained in vegetation canopies. At 2000nm to 2200nm range the Cellulose Absorption Index (CAI) quantifies exposed surfaces that contain dried plant material and has absorption present that could indicate strong presence of cellulose. Canopy water content vegetation indices were also calculated from the response in the NIR with SW to provide an indication of the measured amount of water contained in the canopy. The Normalized Difference Water Index (NDWI) reectance, which occurs at 857nm and 1241nm is known to be strongly related to the plant water content. This is interpreted to the effect that with higher water content often indicates healthier vegetation.The Moisture Stress Index (MSI) is sensitive to the effects of drought or catastrophic wetness increases in leaf water content at the absorption around 1599nm as well at 819nm and 1649nm that describes the Normalized Difference Infrared Index (NDII) values which uses a normalized difference formulation instead of a simplec ratio, with the index value increase with increasing water content. When compared with those spectral response in Landsat 8 OLI of 8 bands and MODIS of 36 bands, it showed that the required response were not present. These spectroscopy based measurements will serve for the purposes in the agricultural development efforts that could result in improved processes in agricultural crop management, plant canopy monitoring, and in the quantifying stressed vegetation.
USC Phil-LiDAR Research Center, University of San Carlos, Nasipit Rd. Talamban, Cebu City, Cebu, 6000, Philippines; Department of Physics, School of Arts and Sciences, University of San Carlos, Nasipit Rd. Talamban, Cebu City, Cebu, 6000, Philippines; Department of Biology, School of Arts and Sciences, University of San Carlos Nasipit Rd. Talamban, Cebu City, Cebu, 6000, Philippines; Department of Geomatics and Analytics, Del Monte Philippines Inc., M.Fortich, Bukidnon, 870, Philippines
