Q-compensated beam migration with multiscale Gabor transform

Anelastic attenuation often causes amplitude decrease and phase distortion in seismic data. Seismic migration of such attenuated data often yields poor images of subsurface structures, especially under high-attenuation areas. Previous studies have been focusing on the compensation of attenuation to obtain higher resolution images. However, it is still challenging to achieve a good ray-based Q-compensated migration for seismic data. In this paper, we firstly introduce the multiscale Gabor transform to obtain a local time-frequency data for Q-dependent compensation, where the local lengths of filtering windows varied from frequencies are computed automatically. Then, we propose an efficient Q-compensated beam migration based on the multiscale Gabor transform. The attenuation of seismic wave is compensated based on Q-dependent traveltimes before imaging loop, and the Q-dependent traveltimes are purchased using the spatial variant Q models within imaging loop. The proposed Q-compensated migration has similar computational cost as the traditional beam migrations, because the frequency integral loop in the imaging process is solved in our implementation scheme. Both synthetic and real data examples show the effectiveness and efficiency of the proposed method.