频域全波形反演能够获得高分辨率的反演结果, 具有较高的计算效率, 因此得到广泛应用。在传统单频点串行反演策略的基础上, 提出一种多频点同时反演策略, 并推导出一种新的目标函数表达式, 应用于频域全波形反演算法中。该策略能够同时反演所有的频率分量, 对于一组频点中的每个频点进行加权求和处理, 从而避免了高频分量在反演结果中占据主导, 同时避免反演结果中存在噪声干扰。分别用三种不同的模型进行验证。实验表明, 相对于传统的单频点策略, 多频点策略的反演结果具有更好的稳定性、正确性和鲁棒性; 而且对于模型中明显介质边界的位置, 它的反演结果更接近于目标模型。

Using frequency-domain full waveform inversion (FWI) can obtain inversion results with high resolution and higher computational efficiency. Based on the traditional sequential single-frequency inversion strategy, a simultaneous multifrequency inversion strategy and a new objective function formula are given in this paper, and they are applied in FWI algorithm. This strategy can inverse all frequency components simultaneously and process weighted sum for each frequency in the frequency group. So high-frequency components can not dominate the inversion results and noise interference can be avoided. Three different models are used for validation in this paper. Experiments show that compared with the sequential single-frequency inversion strategy, the simultaneous multifrequency inversion strategy has better stability, accuracy and robustness. And with regard to profiles with sharp boundaries in the model, inversion results in the former strategy are closer to objective model.