Imaging with adjoint (conjugate-transpose) operators

A secondary theme of this book is to develop in the reader an understanding of a universal linkage beween forward modeling and data processing. Thus the codes here that incarnate linear operators are written in a style that also incarnates the adjoint (conjugate-transpose) operator thus enabling both modeling and data processing with the same code. This style of coding, besides being concise and avoiding redundancy, ensures the consistency required for estimation by conjugate-gradient optimization as described in my other books.

Adjoint operators link the modeling activity to the model estimation activity. While this linkage is less sophisticated than formal estimation theory (``inversion''), it is robust, easily available, and does not put unrealistic demands on the data or imponderable demands on the interpreter.