How I can smooth my fourier amplitude spectra

How to smooth an earthquake fourier amplitude spectra for better interpretation.

Answer 1

[Wayne King]

You can use pwelch() or pmtm() to obtain a smoothed nonparametric estimate. This is recommended, alternatively you can use a parametric method to get a really smooth spectrum, but very sensitive to model misspecification.

Please attach data and the sampling rate and I can show you how to use pwelch() and pmtm().

Both require the Signal Processing Toolbox.

[Khalid Mahmood]

Thanks King, Please find the attached txt file. I am new to signal processing. Your kind help will be really appreciated. Regards

[Wayne King]

Is this the time data or the Fourier amplitude spectrum? It looks like it is the Fourier magnitudes in which case that is very smooth already.

[Khalid Mahmood]

Dear King this is fourier amplitude spectrum. I am interested to get a smooth line on this for better interpretation. Thanks\