Joint inversion of gravity and seismic data based on common gridded model with random density and velocity distributions
密度和速度随机分布共网格模型的重力与地震联合反演

In view of the problems existing in joint inversion of gravity & seismic data and the published research results,we study a model construction method based on common gridded model with random density and velocity distributions to meet the needs of joint inversion and the complicated model with large density and velocity variations.2.5 dimensional gravity forward modeling is fulfilled in accordance with this gridded model.By improving the ray-tracing method in 2 dimensional seismic travel-time computing to suit the gridded media with random velocity distribution,we realize the synchronous joint inversion of gravity & seismic data based on this kind of common gridded model in accordance with the improved very fast simulated annealing algorithm.The model test shows that the joint inversion could accurately determine the density and velocity structures of complicated model with uncommon interface and large variations of density and velocity.Moreover,joint inversion method is clearly superior to the single inversion of gravity data.The joint inversion of the observed data with a priori constraining information also gives good effects,which make it clear that this method is effective and practicable in improving inversion accuracy and reducing ambiguity.