|Preconditioned least-squares reverse-time migration using random phase encoding|
When estimating the Hessian matrix, encoding both the source and receiver sides is more efficient than encoding the receiver side only. Moreover, the source-based Hessian is more accurate than the conventional source intensity function. As a preconditioner, the source-based Hessian is the most efficient due to its cheaper computational cost compared to estimating both sides of the Hessian matrix. However, using this source-based Hessian in different acquisition geometries needs to be further tested.