Hello folks-

I am using the raster calculator to build the NDVI expression (using Arc10.0) because I want the raw values of the NDVI calculation. However, in order to use the raster calculator and get the raw values, I have to change my original landsat input into float images (I used the Math toolbox>Float tool to convert). The resulting output from the raster calculation of NDVI is a 32 bit float image. The NDVI looks great, I can use classified symbology to break up the color ramp and I really like the display, but I want to work with the pixel values to calculate the mean pixel value for the habitat that I have selected. Obviously with the NDVI being a 32bit float I can't build a raster attribute table.

Is there a good way around this?

Ultimately, I want to clip out the areas I sampled, then calculate the mean NDVI across each area. Then I want to remove all the negative NDVI values and calculate the mean of the remaining positive NDVI values and see if either of those NDVI's can be correlated with site use.

Thank you for your help!

~Laura Cockrell

I am using the raster calculator to build the NDVI expression (using Arc10.0) because I want the raw values of the NDVI calculation. However, in order to use the raster calculator and get the raw values, I have to change my original landsat input into float images (I used the Math toolbox>Float tool to convert). The resulting output from the raster calculation of NDVI is a 32 bit float image. The NDVI looks great, I can use classified symbology to break up the color ramp and I really like the display, but I want to work with the pixel values to calculate the mean pixel value for the habitat that I have selected. Obviously with the NDVI being a 32bit float I can't build a raster attribute table.

Is there a good way around this?

Ultimately, I want to clip out the areas I sampled, then calculate the mean NDVI across each area. Then I want to remove all the negative NDVI values and calculate the mean of the remaining positive NDVI values and see if either of those NDVI's can be correlated with site use.

Thank you for your help!

~Laura Cockrell