filter
From Glossary of Meteorology
- Any material that, by absorption or reflection, selectively modifies the radiation transmitted through an optical system.
- To remove a certain component or components of radiation, usually by means of a filter, although other devices may be used.
- A mathematical tool used to remove information within certain frequency (
or wavelength) limits from a time (
or space) series of data.
Filters are commonly used to remove high (low) frequency oscillations from a dataset when oscillations of low (high) frequency are of interest.