3) Noise Removal NR (2.00)

• Provides very aggressive denoising
• Usually parameter-less, but may want to adjust from 2 to 1 to avoid spikes.
• Retains as close as possible original peak resolution
• Excellent for presentation purposes

4) Noise Filtering NF (0.7)

Unfiltered noise is random and uncorrelated, while signals are highly correlated, in that successive y-values progressively reduce from peak tops. The noise-filtering program is designed to identify correlated and uncorrelated features in data so that only the uncorrelated noise components are filtered. The degree of correlation is the only parameter and determines how efficiently the noise is filtered with respect to the signals. This value typical varies from 0 to 1 with a common default of 0.7. Minimum resolution loss across peaks is typically observed.

• Virtually parameter-less, and the default of 0.7 is best for most data.
• Allows resolution to be maintained while reducing noise.
• Retains small peak features near the baseline

 

5) Default smoothing (resolution-based gaussian)                 

 This function is an advance on classical gaussian smoothing.  The filter is changed across the mass range depending upon the resolution setting stated in the peak detection parameters. Classical smoothing will tend to over smooth at the low mass end and under smooth at the high mass end. The program is parameter-less, but is dependent on the setting in the peak detection parameters.

• Best on high mass data where lots of data points across a peak
• Depends on correct peak detection parameters

• NOTE: Do not use on high resolution data (e.g., peptides with well resolved isotope clusters)

6) Smoothing 

This the classical smoothing program which allows user interaction via setting the number of smoothing points (from 3 up to 353). The program defaults to a “suggested” value for the acquired trace (back-highlighted in blue) for ease of use.

• Is a known quantity.
• Allows user input over a wide range
• Data output can be compared with other data outputs