What does NDVI stand for, and what is its primary use?

NDVI stands for Normalized Difference Vegetation Index, and its primary use is in assessing vegetation health. This index is derived from the difference in reflectance in the near-infrared (NIR) and visible (specifically red) wavelengths of light, which allows for the evaluation of vegetation conditions effectively. Healthy vegetation reflects more NIR light and absorbs more red light, resulting in a higher NDVI value. This makes NDVI a valuable tool for monitoring plant health, crop management, and assessing changes in biomass over time.

The use of NDVI is essential in remote sensing applications, such as evaluating agricultural productivity, studying ecological dynamics, and managing natural resources. It provides a clear indicator of the greenness and vigor of vegetation, which correlates directly with plant health and productivity. Thus, option B accurately describes both what NDVI stands for and its main purpose in remote sensing and environmental monitoring.