How to calculate frequency dispersion around median frequency in power spectral density ?

Hi, I need help in finding frequency dispersion around the median frequency. i have plotted the PSD using pwelch. I figured out I can find the median frequency using 'medfreq'. How do I find the frequency dispersion such that 68% of the total power lies in that range. The image shows the type of output I need to calculate. The blue dot represents the median frequency. The blue lines indicate the frequency dispersion such that 68% of the total power lies within the boundaries. Sampling rate is 30Hz Data length is around 450 points. I have zero padded before obtaining fft and psd. I also subtracted the mean from the data before zero padding. Any help in this regard would be helpful. Thanks in advance. Disclaimer : The image belongs to Matthew J.Johnson

Answer 1

[Greg Dionne]

Try Occupied Bandwidth (OBW).

Have a look at the frequency range (FREQRANGE) and percentage (P) arguments to help you customize the portion of bandwidth you want to estimate.