Analysis of numerical implementation of the angular spectrum approach to calculate the acoustic field from rectangular source

The aim of this paper is to study the modeling of the 3-D ultrasonic fields propagation using the angular spectrum approach (ASA). This approach is based on the two-dimensional spatial Fourier transform. It is well known that the numerical implementation of this method results in aliasing errors. Hence, the angular spectrum approach is modified to reduce or to eliminate these errors. In this work we compare the simulation results of ultrasonic field´s propagation given by the simplest ASA algorithm and the modified one. A good accuracy is noted in results from the second algorithm, which demonstrate its efficiency.