# Is it possible to just remove the noisy part of signal?

Is there a way to scan through a signal and remove the parts that don't look "normal". This would mean using more advanced then a simple pass band filter, but something that can look at a period in the signal and remove it if that period didn't fit into a "template".

• What do the red circles represent? If they are not based on a-priori knowledge, it seems they could be useful to determine the positions of the noise parts... Mar 1, 2019 at 14:42
• Those are at the start of each rising signal. If I could figure out how to remove signals that didn't fit into a specific "mold" then I would have a solution, but I don't know if that's possible.
– sgmm
Mar 1, 2019 at 14:52
• Do you have some sort of mathematical model for the "useful" signal (the one you want to preserve) and/or the noise? Think about their properties, and which of them we can use to distinguish the two. We can see that the noise has a much higher amplitude, for example. We can also see that the noise and signal overlap in time, but only at a limited number of samples. You could look at the frequency domain, and see whether or not signal and noise overlap there. As a simple rule: the more "overlap" there is, and the less we know about the form of the signals, the harder it is to remove the noise. Mar 1, 2019 at 15:11
• To add a more practical suggestion: if the amount of samples affected by noise is small, it might be enough to detect those samples (e.g., by comparing the energy in a local window to the mean energy of the signal) and simply discard them. Mar 1, 2019 at 15:14