The phrase true amplitude imaging, as used in this book, really means that, after migration, any amplitude within the imaged volume is directly proportional to reflectivity. There are, of course, so-called true amplitude one-way methods, but all of those methods are simply modifications of a one-way method of choice to include some aspect of two-way propagation. Jon Claerbout was the first to propose such a method in his 1986 book, so the idea of making a one-way migration into a two-way migration has been around for some time. However, as far as the author is concerned, the only methods that can be called true amplitude methods are the full two-way method and the Gaussian beam method.
