AnsweredAssumed Answered

Create NDVI from LANDSAT

Question asked by jpolo on Feb 13, 2015
Latest reply on Jan 6, 2017 by anhpt200

I have downloaded data from LANDSAT 8. I want to create a layer for NDVI. I have read several sources on using the bands for creating the raster.


I started with this:

Calculating NDVI in ArcGIS 10 - Thad Wester

I followed the steps and each time my raster was not what I expected. Then I noticed the NDVI option in the Image Analysis Window and tried that. The resulting raster looks like what I expect, almost all green, since I am looking at a forest. However, the values range from 1 - 100something, when they are supposed to be -1 to 1 at most, so that output is suspect to me.


I searched some more for how to come up with the raster and found this:

ArcGIS Help 10.1

I still can't find the Band Arithmetic function. I rely on the GUI, I don't know anything about programming, so if it's not a distinct tools or menu item, I don't know how to access it.


Looking at the explanation here

ArcGIS Help 10.1

it says that the IR and red bands are defaulted to 3 and 4. I didn't know which was which, Wikipedia says that LANDSAT 8 breaks down where IR is 5 and red is 4. Options lets me change that and I did, but no matter what I do, I can't get a raster that I expect. I've tried Image Analysis Window with different methods and raster calculator under Spatial Analyst.


And I saw this:

Is there a problem with ndvi function in ArcMap 10.2? Not getting expected results.


I am not sure what step to take next.