Time-domain spectroscopy
Time-domain spectroscopy is used very often in infrared spectroscopy (FT-IR) and NMR spectroscopy(FT-NMR).  It has several advantages over frequency-domain spectroscopy.  In frequency-domain experiments, each wavelength must be measured one at a time.  This means scans can take several minutes.  A single time-domain experiment takes no longer than a minute.  Usually it only takes seconds.  This means that many scans may be taken for a given sample, and that the scans can be averaged.  So not only is the time-domain experiment faster, but it can also have a better signal to noise ratio.