Normalized Difference Vegetation Index (NDVI) quantifies vegetation by measuring the difference between near-infrared (which vegetation strongly reflects) and red light (which vegetation absorbs). NDVI always ranges from -1 to +1. But there isn’t a distinct boundary for each type of land cover.What is ndndvi?
NDVI is often used for a quantitate proxy measure of vegetation health, cover and phenology (life cycle stage) over large areas. NDVI is calculated from the visible and near-infrared light reflected by vegetation. Healthy vegetation (left) absorbs most of the visible light that hits it, and reflects a large portion of near-infrared light.How to calculate NDVI using NAIP imagery/reflectance data?
In this case, you need to calculate NDVI using the NAIP imagery / reflectance data that you have. The normalized difference vegetation index (NDVI) uses a ratio between near infrared and red light within the electromagnetic spectrum. To calculate NDVI, you use the following formula where NIR is near infrared light and red represents red light.What is normalized difference vegetation index (NDVI)?
As shown below, Normalized Difference Vegetation Index (NDVI) uses the NIR and red channels in its formula. Healthy vegetation (chlorophyll) reflects more near-infrared (NIR) and green light compared to other wavelengths. But it absorbs more red and blue light.