Implications of evanescent waves for the Marchenko method through the lens of the transferscattering matrix relation

Abstract

The presence of evanescent modes and their impact on the Marchenko method has been until very recently a topic that received little attention. In this contribution we link the concept of the transfer matrix to the fields usually associated with the Marchenko method. Using that formalism, we introduce the concept of a path reversal - a generalization of time reversal for travelling waves, which also encompasses the evanescent modes. We take a first look at the implications the latter may have for the “standard” Marchenko method. It appears that the scheme should perform well, as long as one does not attempt to reconstruct evanescent modes inside the medium (at the target-overburden boundary).