NationMaster - Encyclopedia: FWHM

In telecommunication, a full width at half maximum (FWHM) is an expression of the extent of a function, given by the difference between the two extreme values of the independent variable at which the dependent variable is equal to half of its maximum value.

FWHM is applied to such phenomena as the duration of pulse waveforms and the spectral width of sources used for optical communications.

The term full duration at half maximum (FDHM) is preferred when the independent variable is time.

Source: from Federal Standard 1037C

Categories: Telecommunications

Results from FactBites:

FWHM (245 words)
	The technical term Full-Width Half-Maximum, or FWHM, is used to describe a measurement of the width of an object in a picture, when that object does not have sharp edges.
	An alternative, which better reflects the approximate size of the star's image as seen by the eye, is the width across the profile when it drops to half of its peak, or maximum, value (shown in the graph above).
	In the usual sort of astronomical image, the FWHM is measured for a selection of stars in the frame and the "seeing" or image quality is reported as the mean value.

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