The invention relates to a probe that includes N<；sup>；E<；/sup>； ultrasound transmitters (11) and N<；sup>；R<；/sup>； ultrasound receivers (12) and that is applied on the environment to be characterized. The method comprises consecutively activating each transmitter (11) and each time collecting the signals on all of the receivers (12) during a time window. Each of the collected N<；sup>；E<；/sup>； x N<；sup>；R<；/sup>； signals is converted, by a time Fourier transform, into a sum of vibratory components each having its own time frequency. The method comprises deriving, for each frequency, a matrix N<；sup>；E<；/sup>； x N<；sup>；R<；/sup>； of the complex amplitudes of the vibratory components having said frequency. The matrices (one by frequency) are decomposed into singular values, the smallest ones are removed, and the method further comprises forming, with the singular vectors associated with the remaining singular values, a base of the space of the reception signals for each frequency. The method also comprises calculating the contribution of each planar wave characterized by the speed thereof (space frequency) in said base. Said contribution is represented in the form of a gray level in a frequency-propagation speed system. The invention can be used for better characterizing envrionments, in particular noisy ones.La invención es concerniente con una sonda que incluye NE transmisores de ultrasonido (11) y NR receptores de ultrasonido (12) que es aplicada al medio ambiente a ser caracterizado. El método comprende activar consecutivamente cada transmisor (11) y cada vez recolectar las señales en todos los receptores (12) durante una ventana de tiempo. Cada una de las NE y NR señales es convertida por una transformada de tiempo de Fourier en una suma de componentes vibratorios, cada uno tiene su propia frecuencia de tiempo. El método comprende derivar, para cada frecuencia, una matriz de NE x NR de las amplitudes complejas de
