1.1. Product Description
Chlorophyll Index uses commonly accepted measurements to give an indication of the level of chlorophyll in a plant at any point in its growth cycle. Two methods of Gitelson et al. are typically used, which are based on comparisons of absolute reflectance within narrow green, red, and near infrared bands:
Equation 1: Gitelson green model for determining chlorophyll index
Equation 2: Gitelson red edge model for determining chlorophyll index
A discussion on the background of these two different methods can be found in the Geophysical research letter “Remote estimation of canopy chlorophyll content in crops”, Gitelson et al. 2005.
The first step in calculating chlorophyll index is to separate measurements of reflected photons which interacted directly with plant pigments from other “noise” photons, as previously discussed in above sections on plant segmentation. Once these signals are segmented, the ratio is calculated on a pixel-by-pixel basis and the statistics are computed.
1.1.1. Reporting Method
Mean and standard deviation of chlorophyll index over selected grid size