Lorentzian broadening, resolution enhancement

The type of the line-broadening function (LBF) may be either Lorentzian or Gaussian. The appropriate type depends on the nature of the line broadening mechanism. If in doubt it is recommended to start with a Lorentzian shape. After you have selected a file and wavenumber range as usual in the dialog box (Fig. 10.50), specify on the Adjust Parameter page a deconvolution factor and a suppression factor for the noise, or alternatively, a factor for the bandwidth and the resolution enhancement. Start the function using the Deconvolute button. 

Another approach to resolution enhancement is the use of Fourier self-deconvolution, which is useful when the spectral features are broader than the instrument resolution [97]. This technique is based on the fact that the breadths of the peaks are the result of the convolution of the intrinsic line shape with a broadening function. Deconvolution allows the removal of the broadening. The broadening function is Lorentzian, and deconvolution with a Lorentzian function will lead to a substantial, physically significant narrowing [98]. 

Matched filter The multiplication of the free induction decay with a sensitivity enhancement function that matches exactly the decay of the raw signal. This results in enhancement of resolution, but broadens the Lorentzian line by a factor of 2 and a Gaussian line by a factor of 2.5. 

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