Generalized PP+PS=SS from seismic interferometry

Abstract

PP+PS=SS refers to a method introduced by Grechka and Tsvankin in 2002 that uses recordings of PP and PS reflections between sources and receivers to estimate the SS reflections between those same receivers. Using source-receiver seismic interferometry as a basis, we derive new, dynamically correct expressions relating reflected and converted P- and S-wave recordings to both P- and S-wave sources. We use these expressions to derive a generalized form of relationship between P and S waves, and show that the PP+PS=SS method of Grechka and co-workers is a special case of these new relationships. By considering the simple example of two elastic half-spaces, we illustrate the differences between the special case of PP+PS=SS and the generalized approach derived here. By relating the method to seismic interferometry, it is possible to see further applications of the new relationships in acquisition and processing of P and S waves, and also in the development of new imaging and inversion schemes. © 2012 The Authors Geophysical Journal International © 2012 RAS.