Through pergressive Fourier analysis of samples typical properties of this method are demonstrated. The most important difference from other mostly applied methods is that not only frequences (or period lengths, respectively) and amplitude values are used, but also phase relations of hidden oscillations, analogously to optical imaging when, e.g., a laser is added to lenses so that also phase relations of the wave trains in the optical field are used. In this way, from a three dimensional object not a plane picture is produced, but a picture equivalent to the original.