Vegetation index

A vegetation index (VI) is a spectral imaging transformation of two or more image bands designed to enhance the contribution of vegetation properties and allow reliable spatial and temporal inter-comparisons of terrestrial photosynthetic activity and canopy structural variations.

Many of the indices make use of the inverse relationship between red and near-infrared reflectance associated with healthy green vegetation.

Due to advances in hyperspectral remote sensing technology, high-resolution reflectance spectrums are now available, which can be used with traditional multispectral VIs.

In addition, VIs have been developed to be used specifically with hyperspectral data, such as the use of Narrow Band Vegetation Indices.

Thus, they can be more robust against light variations, shadows or even uncalibrated images if these artifacts exist in the training data.