EFFECTS OF DIGITAL SAMPLING OF SPECTRA

This research was supported by the National Science Foundation.Author Institution: Department of Physics, Michigan State UniversityUndesirable effects of recording insufficient number of samples per FWHH (full width at half line height) include suppression of line height, distortion of line shape, reduced effectiveness of digital Least squares smoothing and the aliasing of narrow spectral features (noise) into broader features. To counter these effects we recommend the prior use of optimum RC (electronic) filtering, the use of multiple sampling, and the recording of approximately 30 samples per FWHH of lines. We have found that multiple sampling, i.e., the integration or sunning of numerous instantaneous A/P conversions per recorded sample is an effective means of reducing the amplitude of noise while preventing aliasing