METHOD AND ACOUSTIC DEVICE FOR MEASURING SURFACE MOVEMENTS
The invention relates to a method for detecting movements of a plurality of points (P) of a surface (21), comprising a measuring step during which an incident ultrasonic wave is emitted into the air towards the surface and an ultrasonic wave reflected into the air by the surface (21) is detected. During the measuring step, each measuring point is illuminated by the incident ultrasonic wave at a multiplicity of angles of incidence, and the reflected ultrasonic wave is detected by a network of receiving transducers (3) comprising a plurality of ultrasonic receiving transducers (3a). The movements of the surface are determined at a measuring point by determining a delay and/or phase shift between two path-forming signals for said measuring point.