Calibration of focused circular transducers using a multi-Gaussian beam model

A new calibration method is proposed for characterizing spherically and cylindrically focused circular piston-like transducers. The calibration procedure employs a single frequency pulse-echo configuration with a large plane reflector. Analytical solutions based-on multi-Gaussian beam model are introduced to predict the received wave distributions, and a least squares fitting method for extracting the effective geometrical focal length and radius from the measurements near the transducer focus is described. The proposed method is easy to implement and can minimize errors due to measurements, uncertainties and material attenuation. Experimental results show good agreements with the theoretical predictions using the calibrated parameters and measurements.