Wavefield equations

The generalized Kirchhoff integral formulae enable the values of the elastic displacement field (equation (13.121)) or vector wavefield (equation (13.125)) to be reconstructed everywhere inside the domain V from the known values of these fields and their normal derivatives at the domain boundary S. 

It is easy to find the exact solution of the wavefield equation within the first layer. As usual, it can be written as a superposition of the incident and scattered fields,... 

I For conciseness, the sccilar acoustic and vector wavefield equations have been combined into single equations in this summary, with alternative subscripts a and v to distinguish them it is understood, of course, that d , A , and Rv n (but not the adjoint operator F. ), would be printed in boldface in separate vector wavefield equations since they refer to 3-D vector elements in... 

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