LAUSR

To improve magnetotelluric (MT) nonlinear inversion accuracy and stabilitythis work introduces the deep belief network (DBN) algorithm. Firstlya network frame is set up for training in different 2D MT models. The network inputs are the apparent resistivities of known modelsand the outputs are the model parameters. The optimal network structure is achieved by determining the numbers of hidden layers and network nodes. Secondlythe learning process of the DBN is implemented to obtain the optimal solution of network connection weights for known geoelectric models. Finallythe trained DBN is verified through inversion testsin which the network inputs are the apparent resistivities of unknown modelsand the outputs are the corresponding model parameters. The experiment results show that the DBN can make full use of the global searching capability of the restricted Boltzmann machine (RBM) unsupervised learning and the local optimization of the back propagation (BP) neural network supervised learning. Comparing to the traditional neural network inversionthe calculation accuracy and stability of the DBN for MT data inversion are improved significantly. And the tests on synthetic data reveal that this method can be applied to MT data inversion and achieve good results compared with the least-square regularization inversion.