A method for mapping fibrous media by propagation of ultrasound from a set transducers, wherein: a number of unfocused incident ultrasonic waves having different wavefronts are emitted； the signals reverberated by the medium toward each transducer are captured； coherent signals respectively corresponding, for each transducer, to contributions coming from different fictitious focal points in the medium are determined； and then the orientation of the fibers is determined by comparing a spatial coherence between said coherent signals, in a plurality of directions.
