Time deconvolution of diffraction effects—Application to calibration and prediction of transducer waveforms

Abstract

The concept of a radiation coupling function is used to write a transducer response that includes the diffraction losses. This concept leads to easy interpretations of experimental observations. In a second part a method is proposed for removing the diffraction effects from the observed transducer response. A linear system approach is taken to define the transducer output signal in terms of successive convolutions. The proposed method, based on a numerical deconvolution of the radiation filter, leads to an absolute calibration of the transducer impulse response. Deconvolved waveforms are presented for circular and annular arrays. Once the intrinsic transducer response is known, a direct convolution enables the prediction of the output signal for any distance transducer/reflector. Comparisons between predicted and observed transient waveforms are given for circular and annular arrays.