Method for calibrating an acoustic antenna

A method for calibrating an acoustic antenna, the acoustic antenna comprising a plurality of transducers, each transducer being configured to generate an electrical signal when detecting an acoustic wave, the antenna comprising elementary transducers distributed over an antenna row or an antenna plane, about a reference transducer, the antenna defining a main axis, passing through the reference transducer, and perpendicular to the antenna row or antenna plane, the method comprising:

• a) placing a calibration source in at least one position with respect to the antenna, the calibration source being configured to transmit a calibration acoustic wave that propagates to the antenna;
• b) measuring signals generated by all or some of the elementary transducers, including the reference transducer, in response to the calibration acoustic wave;
• c) on the basis of the signals measured in step b), determining a temporal phase shift of the signal respectively generated by each elementary transducer, each temporal phase shift being defined with respect to a reference signal measured by the reference transducer;
• d) reiterating a) to c), so that, in at least one iteration, the position of the calibration source is considered to be centered on the main axis;
• the method further comprising estimating an intrinsic phase shift, of each elementary transducer with respect to the reference transducer, the estimating of the intrinsic phase shift comprising:
• e) concatenating temporal phase shifts determined in each step c), with respect to each elementary transducer, so as to form a vector of phase shifts, said vector of phase shifts being stored in a processing unit;
• f) taking into account a change-of-basis matrix, said change-of-basis matrix being stored in the processing unit;
• g) on the basis of the change-of-basis matrix and of the vector of phase shifts, estimating the intrinsic phase shift of each elementary transducer with respect to the reference transducer.