Editing Fourier-transform spectroscopy (section)

{{Short description|Spectroscopy based on time- or space-domain data}}
{{Use American English|date=January 2019}}
{{use mdy dates|date=January 2025}}
'''Fourier-transform spectroscopy''' ('''FTS''') is a measurement technique whereby [[Spectrum (physics)|spectra]] are collected based on measurements of the [[coherence (physics)|coherence]] of a [[Radiation|radiative]] source, using [[time-domain]] or space-domain measurements of the [[radiation]], [[electromagnetic radiation|electromagnetic]] or not.  It can be applied to a variety of types of ''[[spectroscopy]]'' including [[optical spectroscopy]], [[infrared spectroscopy]] ([[Fourier-transform infrared spectroscopy|FTIR]], FT-NIRS), [[Nuclear Magnetic Resonance Spectroscopy|nuclear magnetic resonance]] (NMR) and magnetic resonance spectroscopic imaging (MRSI),<ref>Antoine Abragam. 1968. ''Principles of Nuclear Magnetic Resonance'', Cambridge University Press: Cambridge, UK.</ref> [[mass spectrometry]] and [[electron spin resonance]] spectroscopy. 

There are several methods for measuring the temporal coherence of the light (see: [[Optical autocorrelation#Field autocorrelation|field-autocorrelation]]), including the continuous-wave and the pulsed '''Fourier-transform spectrometer''' or '''Fourier-transform spectrograph'''.
The term "Fourier-transform spectroscopy" reflects the fact that in all these techniques, a [[Fourier transform]] is required to turn the raw data into the actual [[frequency spectrum|spectrum]], and in many of the cases in optics involving [[interferometer]]s, is based on the [[Wiener–Khinchin theorem]].