TRANSIENT CALIBRATION OF UNDERWATER ACOUSTIC TRANSDUCERS

The low-frequency limit normally imposed by a confined water tank in u nderwater acoustic transducers is prominently reduced by applying Pron y's model to the sampled transient data. A new concept to improve the calibration accuracy of transducers with an uneven transmitting respon se is presented, i.e. that variation of transmitting characteristics o f transducers with frequency can be compensated by using devised minim um phase signals. Its effectiveness is demonstrated in the experiments .