1 Topic by ajeetchem

  • ajeetchem
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Topic: s/n ratio

How does mMass calculate signal-to-noise ratio of a peak?

2 Reply by Martin

  • Martin
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Re: s/n ratio

Hi,

BASELINE: is calculated as a median of the points within specified window.
NOISE (noise width): is calculated as a 2 * median of absolute deviations (according to baseline) of the points within specified window.
SIGNAL: is calculated as the measured intensity minus baseline level.

To conclude, s/n strongly depends on your baseline settings.

3 Reply by ajeetchem

  • ajeetchem
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Re: s/n ratio

Thanks Martin.
Definitely mMass is easiest way to calculate s/n ratio. But sometime i found s/n overestimated or under estimated using mMass. I used to calculate s/n ratio manually. Where signal(minus absolute noise) is divided by absolute noise in specified window (apprx 1Da).