The angular spectrum method is a technique for modeling the propagation of a wave field.
[4] Modeling the diffraction of a CW (continuous wave), monochromatic (single frequency) field involves the following steps: In addition to predicting the effects of diffraction,[5][6] the model has been extended to apply to non-monochromatic cases (acoustic pulses) and to include the effects of attenuation, refraction, and dispersion.
Several researchers have also extended the model to include the nonlinear effects of finite amplitude acoustic propagation (propagation in cases where sound speed is not constant but is dependent upon the instantaneous acoustic pressure).
[7][8][9][10][11] Backward propagation predictions can be used to analyze the surface vibration patterns of acoustic radiators such as ultrasonic transducers.
[12] Forward propagation can be used to predict the influence of inhomogeneous, nonlinear media on acoustic transducer performance.