Fourier Integral Operators in Seismic Imaging, Part 3

We will give an overview over FIO methods in seismic imaging. In particular we will explain how to use the calculus of FIOs to detect discontinuities in the sound speed in a seismic imaging problem, and how to deal with caustics. In this week's talk we will explain how to use Maslov's asymptotic representation of the Green's function that was derived last time in order to compute the forward scattering operator. We will describe the canonical relation for the forward scattering operator geometrically and derive criteria under which the normal operator is (microlocally) invertible.