Source variance

what does it mean (source variance) and how can we identify this parameter?

Variance along which dimension?
If you want the variance along time: extract the scouts time series, then load the file in file in Matlab (see the Scripting tutorial) and compute the variance along dimension 2 with Matlab’s functions var or std.

can you detail more Francois? why I should use the scripting tutorial?

What were you referring to as "source variance"?