“Signal” is the term for what you are trying to measure. “Noise” is extraneous information that can Noise by definition is considered random. If it’s not random, but is a systemic element, you can often design around it.
Instead of worrying about how much noise there is, we want to see how much there is relative to our signal. So we compute a Signal-to-Noise ratio (S/N). It is just S/N = Signal strength/Noise level.
You want an S/N ratio of at least 3, and ideally 10 or more, to have an effective detector.
If a single measurement or frame of data has too much noise, you can take multiple frames of the same source to reduce the noise. By adding together frames taken off an unchanging source, you reduce noise. ...