Towards Improving Reverse Time Migration Performance by High-speed Lossy Compression

Seismic imaging is an exploration method for estimating the seismic characteristics of the earth's sub-surface for geologists and geophysicists. Reverse time migration (RTM) is a critical method in seismic imaging analysis. It can produce huge volumes of data that need to be stored for later use during its execution. The traditional solution transfers the vast amount of data to peripheral devices and loads them back to memory whenever needed, which may cause a substantial burden to I/O and storage space. As such, an efficient data compressor turns out to be a very critical solution. In order to get the best overall RTM analysis performance, we develop a novel hybrid lossy compression method (called HyZ), which is not only fairly fast in both compression and decompression but also has a good compression ratio with satisfactory reconstructed data quality for post hoc analysis. We evaluate several state-of-the-art error-controlled lossy compression algorithms (including HyZ, BR, SZx, SZ, SZ-Interp, ZFP, etc.) in a supercomputer. Experiments show that HyZ not only significantly improves the overall performance for RTM by 6.29∼6.60× but also obtains fairly good qualities for both RTM single snapshots and the final stacking image.