Hi Mananze, I am afraid that I'm not following what you mean. Can you give more information about the ellipse evaluation of signatures? Is this some way of examining spectral signatures? Or some way of intepreting polarization signatures for polarimetric SAR data? Since I'm not familiar with your terms, I'm guessing the answer may be that it is not something that ENVI does. But I'd like to hear more details to make sure. - Peg