I have a time-varing signal and I would like to figure out what is the best filter (low-pass, band-pass, high-pass) to apply in order to remove the high frequency component. I've plotted the signal vs time, and then applied fft and pwelch seperately on the signal. Here are the results:
It seems that the frequency domain doesn't give me much more information than time domain. Am I missing something here? Any hint/input would be greatly appreciated.