S-Filter
The S-Filter is used to attenuate the short spatial wavelength structures that may be present in the measurement from sources such as electronic noise or other measurement artifacts. Additionally, some surfaces may physically contain short spatial wavelength structures which are not relevant to the attended application and may affect subsequent analyses. The figure below demonstrates an S-filter used to eliminate the shorter spatial wavelength components comprising the texture.
When only an S-filter is used, the type of filtering is termed Long Wavelength Pass.
