|Memory efficient 3D reverse time migration|
The goal of this investigation was to try and reduce the RTM bottlenecks of 3D wavefield computation and memory transfers. The former of these was vastly reduced by using a series of GPU oriented kernels to perform wave propagation in a massively parallel sense, a total speed up of 30x was seen. The memory transfer data handling problem within RTM was diminished by using increasingly random boundaries on the velocity model to produce time-reversable wavefield modeling, alleviating the method from the intensely IO bound technique of checkpointing. A simple 2.5D single reflector model showed an encouraging RTM result, which demonstrates that random boundaries in 3D do indeed provide results comparable to checkpointing; work is underway to obtain detailed images of more complex velocity structures.