The signal I'm studying has fundamental frequencies of 20 and 60 cycles per minute (shown in the Periodogram graph). It is straight forward to extract the peaks in the time domain belonging to the 20 cycles/minute frequency (both are circled), however the peaks associated with the 60 cycles per minute frequency can be noisy.
6 seconds of the time domain signal
Both signals in the time domain will ALWAYS overlap so low pass filtering isn't completely necessary but I'm just curious to know if there's a better way of extracting the 60 cycles per minute peaks (aside from peak-to-trough analysis) using frequency domain information?
Thanks!

