Acoustic propagation modeling using the extended angular spectrum method

The extended angular spectrum method is a technique for modeling the propagation of acoustic fields between parallel planes. The technique may be used to predict an acoustic pressure field distribution over a plane, based upon a known pressure field contour at a parallel plane. The technique has been used to "backward propagate" measured fields to determine the particle velocity distributions at transducer surfaces. However, the results of comparing "forward propagated" fields with those measured have been less successful. Recently improvements have been made to the model and to the associated experimental system which have greatly improved the forward prediction ability. The results demonstrate the ability of the extended angular spectrum method to accurately predict acoustic field contours in the forward propagation case.