Integral equation method in acoustic wavefield analysis

1 Integral equation method in acoustic wavefield analysis 

1 Separation of the acoustic wavefield into incident and scattered (background 

Let us consider an acoustic medium. The propagation of acoustic waves can be described by the scalar wave equation 

The time domain pressure variations, P r,t), can be represented as a superposition of frequency domain signals, p(r,w), using the inverse Fourier transform  

In the frequency domain, equation (14.1) can be written as the Helmholtz equation 

---