Fourier Transform Spectroscopy - Converting Spectra From Time Domain To Frequency Domain

Converting Spectra From Time Domain To Frequency Domain

S(t) = \int_{-\infty}^\infty I(\nu) e^{- i\nu 2\pi t}\,d\nu

The sum is performed over all contributing frequencies to give a signal S(t) in the time domain.

I(\nu) = \int_{-\infty}^\infty S(t) e^{i\nu 2\pi t}dt

gives non-zero value when S(t) contains a component that matches the oscillating function.
Remember that

Read more about this topic:  Fourier Transform Spectroscopy

Famous quotes containing the words converting, time, domain and/or frequency:

    “A way of certifying experience, taking photographs is also a way of refusing it—by limiting experience to a search for the photogenic, by converting experience into an image, a souvenir. Travel becomes a strategy for accumulating photographs.”
    —Susan Sontag (b. 1933)

    “For of those [cities] that were great in earlier times, most of them have now become small, while those which were great in my time were small formerly.”
    —Herodotus (c. 484–424 B.C.)

    “No domain of nature is quite closed to man at all times.”
    —Henry David Thoreau (1817–1862)

    “The frequency of personal questions grows in direct proportion to your increasing girth. . . . No one would ask a man such a personally invasive question as “Is your wife having natural childbirth or is she planning to be knocked out?” But someone might ask that of you. No matter how much you wish for privacy, your pregnancy is a public event to which everyone feels invited.”
    —Jean Marzollo (20th century)