What is the difference between NDVI and WDRVI?

Normalized Difference Vegetation Index, or NDVI, is commonly used in agriculture to quantify vegetation by measuring levels of near-infrared and red light.

Wide Dynamic Range Vegetation Index, or WDRVI, works by similarly measuring levels of near-infrared and red light but is at least three times more accurate than NDVI because it is able to pick up on subtle differences in the crop canopy in moderate-to-high vegetation density, which is especially important for crops with dense canopies and mature crops.