A simplified atmospheric correction procedure for the normalized difference vegetation index

Accurate corrections of the Normalized Difference Vegetation Index (NDVI) for atmospheric effects are currently based on modeling the physical behavior of radiation as it passes through the atmosphere. An important requirement for application of the physical models is detailed information on atmospheric humidity and particles. Here, a method is described for making atmospheric corrections without the need for detailed atmospheric observations. A simplified procedure for making atmospheric corrections to reflectances observed from satellites is developed by using the unique spectral signature of water pixels in satellite images. A radiative transfer model is applied to a variety of clear-sky conditions to generate functional relationships between the radiation due to the atmospheric scattering above water bodies and atmospheric radiative properties. Test cases indicate that the resulting estimates Of surface reflectances and NDVI agree well with estimates made using a radiative transfer model applied independently and with measurements made at the surface.