I. Introduction
The use of ultrasonic transducer arrays has become a fundamental NDT tool [1]. The most commonly used type are linear arrays, composed of a linear arrangement of piezoelectric elements [2] capable of focusing and steering an ultrasound beam in a plane by the activation of its elements with an appropriate set of delays, known as focal law. Less frequent in NDT is the use matrix arrays: 2D arrangements of elements that are capable of beam steering in all space directions, allowing the inspection of more complex components [3].