https://doi.org/10.1351/goldbook.08248
The appearance of peaks at incorrect frequencies in a mathematically-processed spectrum due to insufficient density of datapoints in the time-domain spectrum or from peaks outside of the sampled frequency range.This process can be simulated by folding a spectrum that shows the correct wavenumbers back onto itself at and its multiples.
Notes:
- Folding is a consequence of undersampling in spectroscopy.
- In vibrational spectroscopy, when a spectrum is sampled correctly only up to a wavenumber
, radiation of wavenumber appears to have a wavenumber between 0 and , per the table below:
See also: Nyquist criterion
Range of wavenumber | |
---|---|
[ | 2 |
[2 | |
[3 | 4 |
[4 |