I have a signal which was sampled using different frequencies. The 3 regions are:
- 0-10 ms: 10000 Hz
- 10-50 ms: 1000 Hz
- 50-200 ms: 100 Hz
The signal is very noisy, so I thought about smoothing it with a low pass filter. I worked with each of the 3 regions independently:
- Apply window in time domain (Hann window)
- Apply half Hann window, to remove high frequencies
Each of my regions looks better now but I am having problems stitching them back together, due to the beginning and end of each stage deviating considerably from the original values.
What is the standard procedure of applying a low pass filter to a signal sampled at different frequencies during several stages?
In case it might be relevant, this is the half Hann window used as a low-pass filter. The window length (in the example, 50) is different for every region. I am not interested in a specific cut-off frequency; the filter is used to remove noise and I am evaluating the output visually.