The invention relates to a method and device for determining a detection mode for an element that reflects ultrasonic waves, characterized in that it comprises at least the following steps: for each point P of a given volume Zr, determining an ultrasound field value (I) for N pairs (i, j) of transmitters/receivers and, for a detection mode m, calculating a number of reflections of the wave (II) (III) with (IV) the normal formed by the "outgoing" (V) and "return" (VI) directions of the ultrasound wave transmitted and reflected by the reflecting element, calculating the energy value (VII) for each point P of the zone Zr, with (VIII) and for several modes m with (IX) comparing the energy values (X) obtained at one or more threshold values Es, selecting the energy value(s) that verify the threshold value condition(s), and deducing a mode to use for constructing a representation of the reflecting element.
