New to signal processing, but I've been forced into it a bit as part of my education. I'm collecting low frequency samples in the magnetic field, from 1 to 1000 Hz.
It is stored in MIDAS files, which I handle in Python to produce a PSD. What I'd like to do is get a single frequency observe it over time and compare differences.
As an example, the PSD is 1 to 1000 Hz, and I see a spike at 400 Hz. I'd like to take the raw data used to calculate the PSD and extract only whats going on at 400hz and see the signal, and possible convert it to audio (I can convert it to audio easy).
From what I gathered and have read, I need to apply a band pass filter, but I'm unsure how. Any other methods or examples of how to do this that can be shared?