An estimator of focal position based on geometric acoustics

Abstract

In order to characterize ultrasonic (US) transducers, several aspects may be studied, such as the shape of the beam in space, the US intensity along the central axis and the US intensity parallel to the face of the transducer. With focused beams, a focal region is usually defined. The need for a unique point in space to represent the focus may arise in theoretical models (for example, in geometrical acoustics).In this paper we present a least mean square method to estimate the focal position of US beams in two dimensions (2D) and some simulated and experimental results.