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I am new to ArcGIS.

I have a group of polygons with attribute tables and I have generated an NDVI map [Edit: by NDVI map i mean a File Geodatabase Raster Dataset with 10980x10980 resolution, 1 band, cell size 10x10, format FGDBR, 32bit, without compression with values from -1 to +1 ] from the whole area. I now need to calculate the mean NDVI value for each region of interest/polygon and then assign the value calculated to the tables accordingly.

How can I do that?

  • So you have NDVI as raster cells and want to calculate the mean NDVI from the rasters for a given polygon/area? – GISKid Nov 24 '16 at 18:10
  • yes GISKid, thats correct – ODstuck Nov 25 '16 at 8:58
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Using Zonal Statistics as Table tool you can get the mean NDVI value for your polygons (Zones). Select the unique polygon name field as zone field in the tool options. The tool creates its own table and then you can join the mean values to your polygon table by using Join field tool and selecting the common polygon name field to make the join between the two.

  • Thank you very much for the quick answer Salman. However i have tried the Zonal Statistics as table tool and it returns an error: "Invalid input geodataset" which is the field i put my NDVI map – ODstuck Nov 24 '16 at 16:46
  • To be more specific, what i did was this: 1)Input raster or feature zone data: The table with the ROIs 2)Zone field: the key value id 3)Input value raster: The NDVI map – ODstuck Nov 24 '16 at 16:50
  • @ODstuck this answer is correct, however you haven't provided enough information about your "NDVI Map". Please edit your question to specify the format of the NDVI data (is it a raster? what raster format is it? etc...) – user2856 Nov 24 '16 at 20:40
  • Thank you Edit: by NDVI map i mean a File Geodatabase Raster Dataset with 10980x10980 resolution, 1 mand, cell size 10x10, format FGDBR, 32bit, without compression with values from -1 to +1 – ODstuck Nov 25 '16 at 8:58
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    Haha indeed restarting ArcGIS is always the final (and often successful) weapon when everything else fails. – Salman Nov 25 '16 at 12:46

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