Abstract: A method of testing an acoustic array antenna, consisting in using at least one independent acoustic transducer of non-directional type for receiving the same signal simultaneously via the transducer and via the antenna, and in comparing the received signals to identify possible fixed echoes and to verify whether or not the antenna and its associated cabling, relay, amplification, and signal generating and processing means are in a nominal operating state.

Abstract: A method of remotely determining the three-dimensional velocity of a fluid such as air or water, the method consisting in emitting signals of determined frequencies in at least three different directions by means of a plane array of transducers, and in using said transducers to pick up acoustic signals backscattered by the fluid, the method consisting in emitting trains of signals at different determined frequencies f1, f2, and f3, firstly in a determined direction D1, then in a determined direction D2, and finally in a determined direction D3, and subsequently in picking up all of the signals backscattered by the fluid. The invention makes it possible to improve the accuracy and to increase the maximum range of measurements.