抄録
This paper describes estimation of vegetation cover rates and vegetation vigor independently by spectral reflectance. In the study of plants by remote sensing, Normalized Differential Vegetation Index (NDVI), Perpendicular Vegetation Index (PVI) and Vegetation Index (VI) have been commonly used. These indexes, which use the reflectance of red and near infrared, indicate the information about vegetation cover rates and vegetation vigor inclusively. Therefore, we made experiments to estimate vegetation cover rates and vegetation vigor independently using manilagrass in the growth cabinet. The results show that the reflectance around 550 nm and 980 nm is not affected by vegetation vigor but vegetation cover rates. The authors derive new indexes based on the result. Vegetation Cover Index (VCI), which is the reflectance difference between 550 nm and 980 nm, indicates vegetation cover rate independently of vegetation vigor. Vegetation Vigor Index (VVI), which is the ratio of PVI to VCI, indicates vegetation vigor independently of vegetation cover rates. The other experiment using sorgo shows the applicability of the new indexes to other crops in the field.
