Spectrogram Analysis

A spectrogram (also called a time-frequency representation, waterfall plot, or colormap) is a 3-dimensional graph that describes the signal according to time, frequency, and level.

Time is displayed as abscissa, frequency as ordinate. The level is displayed using a Colormap. The calculation of the spectrogram is done using a Short-Time Fourier Transform (STFT), a special case of the general Gabor transform.