In which range are NDVI data values typically collected?

NDVI, or Normalized Difference Vegetation Index, is a widely used remote sensing index that measures vegetation health and density. The formula for calculating NDVI is (NIR - RED) / (NIR + RED), where NIR represents the near-infrared light reflected by vegetation and RED represents the visible red light.

The resulting values of NDVI typically range from -1 to 1. Negative values, which can occur for non-vegetated surfaces such as water bodies or barren land, indicate little to no vegetation. Values closer to 0 suggest sparse vegetation, while positive values indicate varying degrees of vegetation health, with higher values (closer to 1) representing dense and healthy green vegetation.

This range of -1 to 1 allows for a comprehensive assessment of vegetation cover and health, facilitating effective monitoring of ecosystems and agricultural areas. The other ranges presented in the question do not accurately reflect the potential values of NDVI, as they either extend beyond the realistic bounds of the index or fall short of capturing the full spectrum of vegetation response measured by NDVI.