Multiscale full-waveform inversion based on shot subsampling

• Published in: Applied geophysics Vol. 15; no. 2; pp. 261 - 270
• Main Authors: Shi, Cai-Wang, He, Bing-Shou
• Format: Journal Article
• Language: English
• Published: Beijing Chinese Geophysical Society 01.06.2018; Springer Nature B.V; Key Lab of Submarine Geosciences and Prospecting Techniques, Ministry of Education, Qingdao 266100, China; Evaluation and Detection Technology Laboratory of Marine Mineral Resources, Qingdao National Laboratory for Marine Science and Technology, Qingdao 266071, China; Ocean University of China, Qingdao 266100, China
• Subjects: Computational efficiency; Computer applications; Computing time; Crosstalk; Data; Earth and Environmental Science; Earth Sciences; Frequency domain analysis; Geophysics/Geodesy; Geotechnical Engineering & Applied Earth Sciences; Iterative methods; Mathematical models; Modelling; Noise; Robustness (mathematics); Waveform; shot subsampling; inversion; frequency
• ISSN: 1672-7975; 1993-0658
• DOI: 10.1007/s11770-018-0669-6

Conventional full-waveform inversion is computationally intensive because it considers all shots in each iteration. To tackle this, we establish the number of shots needed and propose multiscale inversion in the frequency domain while using only the shots that are positively correlated with frequency. When using low-frequency data, the method considers only a small number of shots and raw data. More shots are used with increasing frequency. The random-in-group subsampling method is used to rotate the shots between iterations and avoid the loss of shot information. By reducing the number of shots in the inversion, we decrease the computational cost. There is no crosstalk between shots, no noise addition, and no observational limits. Numerical modeling suggests that the proposed method reduces the computing time, is more robust to noise, and produces better velocity models when using data with noise.