Near-surface tomographic velocity analysis method

The invention discloses a near-surface tomographic velocity analysis method. The near-surface tomographic velocity analysis method comprises the following steps: picking up travel time of first arrival by aiming at pre-stack data, and obtaining an initial model reflecting underground medium velocity distribution by pre-stack processing; performing a shortest path ray tracing method on the model to obtain simulated travel time; performing wave field simulation on the model by utilizing a frequency domain wave equation to obtain a sensitive kernel function reflecting disturbance of a medium to the travel time; establishing a corresponding inversion equation and solving to obtain a slowness updating amount. According to the tomographic velocity analysis based on the Fresnel zone, the problem that the solution of a large-scale sparse matrix is instable during the traditional temographic velocity analysis based on the ray theory is solved, and the seismic wave propagation rule is more truly portrayed; the near-surface tomographic velocity analysis method has the advantages that the physical geography significance is obvious, the stability is strong, the efficiency is high, and calculation results are more real and reliable.