VI (Vegetation Index, ดชั นีพืชพรรณ):
Conversely, it has been shown that an inverse relationship exists between the response in
the visible region, particularly the red, and plant biomass.
The relationship between red and near-infrared canopy reflectance has resulted in the
development of numerous remote sensing vegetation indices (e.g., NDVI) and biomassestimation
techniques that utilize multiple measurements in the visible and near-infrared
region (Lyon et. al., 1998).