Joint Distributed Traveltime and Full Waveform Tomography for Enhanced Subsurface Imaging in Seismic Networks

Imaging the subsurface of extra-terrestrial bodies and planets has gained significant attention in recent space exploration missions. Multi-agent systems that autonomously perform subsurface imaging have been proposed. There, agents collaborate to image the subsurface by leveraging their wireless connections, enabling each agent to obtain an estimate of the subsurface image. However, traditional subsurface imaging techniques rely on a single entity for data collection and inversion, making them centralized schemes that limit direct availability of subsurface images at the agents. In this article, we propose the joint use of distributed seismic imaging techniques based on traveltime tomography and full waveform inversion, namely, the distributed traveltime tomography (D-TOMO) and the adapt-then-combine full waveform inversion (ATC-FWI). Combined in a sequential manner these techniques allow each agent to infer high-resolution subsurface images by exchanging data with their neighboring agents starting from a simple initial subsurface model. Unlike existing decentralized seismic imaging methods, our proposed scheme is fully distributed and provides flexibility without the need of anchor nodes or a full mesh topology. We demonstrate that ATC-FWI can recover high-frequency components based on a low-resolution subsurface image provided by D-TOMO in the initial stage. To assess the imaging performance, we employ a synthetic model, the SEG/EAGE salt model as well as real data from field measurements conducted over a tunnel.