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I have land cover rasta data for the years 2000, 2010 and 2014. I would like to get the NDVI for each of the year. I have to generate the RGB first. I have tried the following things: 1. layer -> Export data -> Use Renderer -> Force RGB (format -> tiff) then Save (Arcgis 10.1 can not execute the command)

  1. Windows -> Image Analysis -> tick against the data (2000 or 2010 or 2014) -> click on it to highlight -> from here I understand that I need to go to the 'Composite Band' icon at the bottom, but this is active, so I can't click on it to command the execution of the operation.

  2. The third last thing I have tried is to combine all the three data sets (2000, 2010, 2014) using way 2 above. Combining the three years makes the 'Composite Band' to be active. But this won't allow me to understand the NDVI for each of the years, separately.

What should I do to get the RGB for each year (and eventually NDVI), separately, having tried the above?

2

You cannot calculate NDVI from land use/cover maps because they are an output of satellite image analysis. You need to get the raw images first of the sensor of your interest and start analyze the raw data. However, you need to do some pre-processing of the raw images in order to be suitable for calculating NDVI.

It looks like you misunderstood how NDVI can be calculated. NDVI is calculated using band ratio between red band (R) and near infrared band (NIR) using the following formula:

NDVI = (NIR-R)/(NIR+R)

The band numbers that represent NIR band or R band are different among sensors. The link above can give an explanation on how NDVI can be calculated.

  • Hi, many thanks. I think I did get it wrong because I thought I could calculate NDVI from land use/cover maps. Many thanks for this. – Andrew Jan 24 '17 at 13:06
  • Please accept the answer so others know it is settled. – ahmadhanb Jan 24 '17 at 13:14

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