Abstract:Crosshole seismic data image using wave equation inversion is achieved by adopting Gauss-Newton regularization method. In this technique,we need not repeatedly solve wave equation for forward estimation of each shot,but combine the traces of some shots to form new group of traces,called post-addition seismic traces. We may say that the post-addition seismic traces are equivalent to those which are obtained by simultaneously shooting at all shot points. Then all the forward estimations can be finished by once solving for the wave equation. The inversion image can be achieved in the similar way. Neither any supposition on the matherratic model is necessary nor harsh requirement for initial values is needed in the technique. The technique uses not only the travel-time informations of first arrivals but also the informations of transmitted wave and reflected wave,so that image resuit has quite good accuracy.