How do I normalize raster data?

Discussion created by tayler.hamilton on Jan 26, 2012
Latest reply on Mar 16, 2012 by wenpro70
I want to combine different raster layers, but need the data to be measured at the same numerical scale. Therefore, I would like to normalize all of the different layers so I can add them together, and then renormalize them.

I am not very good with statistics in general, and am unsure of how to even normalize a data set. I know there are multiple equations to do this, but don't know which one is right for me.

But if we were to use the equation:

Z = X - u / std

Where, Z - the normalized value;
u - mean; and,
std - standard deviation;

How would I calculate this in a raster?

I have tried using "Calculate Statistics" (Data Management Tools) because I assumed it would calculate mean and standard deviation for me, but I don't know where the output goes, as I can't choose that in the window. Also, the information on what this tool actually calculates is pretty limited in desktop help.

I have thought about using Focal Statistics to calculate mean and standard deviation individually, but I run into the problem of what scale to use - I want it to include the entire raster in the calculation. This tool would give me different outputs for mean and standard deviation, which I could then put into the raster calculator to solve the normalization equation.

Can someone please let me know if using Focal Statistics is the best way to go about this? Am I even using the right equation to normalize my data?

Any input is GREATLY appreciated!!