基于各向异性Radon变换的叠前地震数据重建

基于常规双曲Radon变换进行叠前地震数据重建时,即使分辨率很高也难以得到准确的中远偏移距数据,因为地震信号同相轴在偏移距较远时已经不再满足双曲线假设。提出基于各向异性Radon变换,即由偏移距、慢度、非椭圆率三参数控制的各向异性Radon变换进行叠前地震数据重建的方法,考虑了偏移距较远时地震数据的非双曲线同相轴,通过稀疏约束控制Radon变换提高了地震数据的重建精度。针对时变Radon变换耗时较长的问题,在算子求解过程中采用快速迭代软阈值算法(Fast iterative shrinkage-thresholding algorithm,FISTA)加快了收敛速度,提高了计算效率。模拟数据和实际数据的应用结果表明,各向异性Radon变换方法在提高数据重建准确度和计算效率方面效果良好。

Although the conventional hyperbolic Radon transform owns high resolution to reconstruct seismic data,it is difficult to reconstruct the far-offset seismic data,because the event of far-offset seismic signals is no longer satisfied with the hyperbolic assumption.Therefore,we proposed a prestack seismic data reconstruction method by anisotropic Radon transform to consider the effect of far-offset factor.The formula of anisotropic Radon transform is controlled by offset,slowness and anellipticity.The travel-time curve of horizontal layer can be accurately described for far-offset by the anisotropic anellipticity parameter of the non-hyperbolic moveout formula.We also use sparsity constraint to improve the accuracy of reconstruction.During the procedure of operator solving,fast iterative shrinkage-thresholding algorithm (FISTA) is used to speed up the convergence and reduce the calculation time.The results of theoretical model and field data demonstrate that anisotropic Radon transform has good effect on the reconstruction accuracy and calculation efficiency.

国家自然科学基金项目(41204078)资助。