Reciprocity principle in finite difference modelling of waves in elastic media

Abstract

Reciprocity principle has been used in a number of seismic applications. This principle relates the two wave fields with interchanged source and receiver locations, where the radiation patterns of the source and receiver are interchanged as well. In extending this principle to be used in real-world scenarios where radiation patterns vary in different locations, a number of experiments to determine the validity of this principle were conducted. Given the proliferation of the numerical modelling in today's geophysical data processing and imaging, the verification of validity of the reciprocity theorem for the modelling algorithms is important. We found that the reciprocity principle is not upheld for some instances of finite difference modelling due to the implementation of the free surface boundary condition. In the case of absorbing boundary conditions however, good reciprocity relation can be achieved.