I'm trying to study vibrations in a non-stationary shaft by upsampling the original signal.
The original sample rate is at 25.6kHz, and it is being upsampled to 36kHz. In the FFT of the upsampled signal I am getting freq. components above the Nyquist frequency of 12.8 kHz. I'm using linear interpolation when upsampling.
Is this imaging/aliasing? What are common techniques for dealing with such behaviour? I'm working in python/matlab.
- Would scipy.signal.resample_poly.html be sufficient?