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While performing raster calculator operation in ArcGIS for Advanced Vegetation Index ( in calculating forest canopy density), the results show only 2 values i.e high (1) and low ( 0), instead of a range of values.The low values considered are of that of the background no-data values.

What could be the possible problem in the operation ?

I am using the formula :

AVI = (("ref5"+1) * (256-"ref4") * ("ref5"-"ref4")) ^ (1/3)

where ref5, ref4 are bands 5, 4 corresponding to Landsat 8 image, converted into TOA reflectance values.

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I think the equation in the raster calculator should be written as follows:

(("TOA_B5.tif"+1) * (256-"TOA_B4.tif") * ("TOA_B5.tif"-"TOA_B4.tif"))**(1.0/3.0)
  • **: means power
  • convert (1/3) integer division into float division (1.0/3.0)

You need to change "TOA_B5.tif" and "TOA_B4.tif" to the corresponding layer names exist in the table of content in ArcMap

  • I updated my answer, you need to remove AVI = in raster calculator. The above equation was tested and should be OK – ahmadhanb Feb 26 '18 at 7:39
  • Hi. Thank you. Can you please tell me what formula have you used to get the TOA_B5 values ? – Prabhashini Mohapatra Feb 26 '18 at 8:27
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    @PrabhashiniMohapatra that is another question different from the one you asked. In GIS.SE, you can ask only one question at a time. If you have a new question, you need to write on a separate thread. Please prepare a detailed question of what have you tried and what formula you used when calculating the TOA. – ahmadhanb Feb 26 '18 at 8:55
  • Hi. I tried this formula but I'm still getting the same results. – Prabhashini Mohapatra Feb 27 '18 at 6:23
  • What is the format of your raster data? I used tif as you can see in my answer. – ahmadhanb Feb 27 '18 at 6:27

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