Migration Methods with Curved Coordinate Systems

Abstract

Reverse time migration (RTM) is a method developed for performing non-invasive physical imaging. It aims to generate diagnostic images based on forward and backward modeling of waves, which can be solved with different type of techniques. A widely used one is Finite Differences (FD) due to its low computational cost and its simplicity, as compared to other methods, to implement. In this work we show how to implement RTM with curved coordinates using FD. In particular we focus on the application of curved coordinates to improve the quality of the resulting images and reduce the computational cost of RTM. Here, we apply a strategy to curve coordinates during the wave propagation modeling stage for a modified version of the Marmousi model. The results show that it is completely feasible the redistribution of grid nodes to locally improve quality of the migrated models and reduce the number of grid nodes at the same time. We also found that typical issues associated to the imaging condition and FD scheme remain.