A picture portraying the construction of a time-frequency representation of the LIGO data. The data is broken into subsections, each subsection is Fourier transformed, and its power spectrum as a function of frequency is plotted vertically. The horizontal axis labels which subsection the spectrum is for, i.e. the time. The result is a picture that show the power of the data at each time and at each frequency.
Picture by Warren G. Anderson, University of Wisconsin-Milwaukee, © 2000.