Reverse Time Migration (RTM) is a computational technique used primarily in the field of seismology for subsurface imaging. The method is popular in the oil and gas industry for locating hydrocarbon reservoirs but is also used in geophysical research and environmental studies. Here are some key characteristics: 1. **Objective**: The main aim is to create accurate images of the subsurface geological structures. 2. **Algorithm**: It involves backward propagation of seismic signals, essentially reversing the time axis, to simulate how the waves would have traveled through the subsurface. 3. **Data Utilization**: RTM uses the recorded seismic reflection data to construct images. 4. **Computational Demand**: Though not as computationally intense as some other techniques like Full Waveform Inversion (FWI), it still requires significant computational resources. 5. **Initial Model**: Less sensitive to the initial velocity model when compared to techniques like FWI. 6. **Resolution**: Provides good structural images but might lack in resolving finer details, depending on data quality and processing techniques. 7. **Sensitivity**: Focuses on imaging reflectors and doesn't incorporate full waveform information, which makes it less sensitive to certain parameters than FWI. 8. **Applications**: Used mainly for the final imaging stage after a reasonably good subsurface velocity model has been constructed, sometimes using techniques like FWI for that purpose. References: - ["Reverse Time Migration with Optimal Checkpointing"](https://library.seg.org/doi/full/10.1190/1.2793740) - ["An Overview of Full-Waveform Inversion in Exploration Geophysics"](https://pubs.geoscienceworld.org/geophysics/article-abstract/74/6/WCC1/281457)