Noise Statistics details
The Noise Statistics calculates the Signal/Noise ratio and some other statistic values of one or more data objects available in the current data view. The Signal/Noise ratio can be calculated for a particular spectral region or the whole data range.
The Noise Statistics command is available in the Mathematics menu.
Noise Calculation Algorithms
Some characteristic values are calculated for the noise statistics result:
Mean Value
The mean value M calculates the mean of all intensities Si in a user defined spectral range of interest. The following equation is applied:
Where
M: Mean intensity value
N: Number of data points in range
Si: Intensity values
Peak-to-peak Deviation
The peak-to-peak deviation is calculated from a linear least squares fit among a spectral windows. Calculation considers the baseline respectively. The following equation is used:
Where
Dp-p: Peak-to-peak deviation (baseline corrected)
(Fcenter-Fwing .. Fcenter+Fwing): Specifies start and end point of the range of interest
Yi: Linear function determined from a linear least squares fit among data points.
Si: Intensity values
Standard Deviation
The standard deviation for baseline-corrected data is calculated from the following equation:
Where
Dst: Standard deviation
N: Number of data points in range
Si: Intensity values
Yi: Linear function determined from a linear least squares fit among data points.
Signal to Noise Ratio Peak-to-Peak
The signal to noise ratio peak-to-peak is calculated using the following equation:
Where
SNRp-p: Peak-to-peak Signal to Noise Ratio
M: Mean intensity value
Dp-p: Peak-to-peak deviation (baseline corrected)
Signal to Noise Ratio Root Mean Square Error
The root mean square error (RMS) for the signal to noise ratio is calculated using the following equation:
Where
SNRRMS: Signal to Noise Ratio Root Mean Square Error
M: Mean intensity value
Dst: Standard deviation