Simple steps to calculate the NDVI, using Erdas. NDVI stands for Normalized Difference Vegetation Index; it is an index commonly used to investigate the characteristics of the vegetation, biomass, and others.
The following tutorial presents detailed explanation accompanied with snapshots. The acknowledgements are the same of the previous entries (Buitron and Fernandez, 2012). The copyrights are shown in the bottom of the page.1. In ERDAS, open the image that has been corrected for atmospheric effects. Make an AOI.
3. In Input File, search for the image you want to analyze (e.g., l520030830_clip.img). In Output File create a folder named NDVI and save the image with a different name (e.g., l520030830_ndvi.img). In SelectFunction, select NDVI and OK.
4. The output image is on gray scale. In the attributes table you will see the NDVI values, (you should confirm that the range is from -1 to 1). THE END.