First-arrival traveltime and amplitude calculation from monochromatic two-way wave equation in frequency domain
利用单频双程波动方程计算初至走时及其振幅

By adding one complex frequency (real part is frequency and the imaginary part is damping factor) into the frequency-domain wave equation, the energy or amplitude after first-arrival wave can be damped. Therefore, the first-arrival traveltime and amplitude can be transformed into the pick of maximum energy and its amplitude in the monochromatic wavefield. Then, the first-arrival traveltime and amplitude can be extracted from the phase and amplitude of monochromatic frequency-domain wavefield. In order to obtain the optimum combination of the frequency and damping factor, we propose a parameter analysis scheme for all possible combinations. The numerical examples are compared with finite-difference eikonal solvers and most-energetic amplitude. The results show that our algorithm has good applicability to multi-shot and multi-receiver computation in complex media.