How to measure algorithmically side lobes in real data I want to measure algorithmically the following parameters in a given FFT data (real numbers).


peak side lobe levels
side lobe levels
 side lobes nulls


The following image illustrates parameters I need.



How I can compute those values using Matlab or Python?
Zero pad your FFT (append zeros) such that you get more samples of the Discrete Time Fourier Transform (DTFT). The DTFT would give you the sidelobes and roll-off that you want to see (specifically for your diagram you would zero pad an input that is all ones, or an input that is any constant value).