Two-dimensional Joint Inversion Of Frequency-domain Airborne Electromagnetic And Magnetic Methods

Synchronous inversion of resistivity and magnetic susceptibility in Frequency-domain Airborne Electromagnetic and Magnetic Methods(FAEM)is an approach that updates the resistivity model and susceptibility model in one iteration at the same time.Joint inversion is an approach based on various physical properties,which achieves inversion through the mutual constraint of model parameters.It can suppress the noise and reduce the multiplicity of solutions.In this paper,we apply the FAEM and magnetic method to explore joint inversion by the research of international primary geophysical joint inversion method.FAEM is one of the electrical prospecting methods,which is considering the artificial source.Therefore,based on a CSAMT two-dimensional forward algorithm,this paper developed a two-dimensional forward algorithm of FAEM and added the susceptibility model to the traditional algorithm.Data space Occam algorithm is used in inversion,which can carry out synchronous inversion of resistivity and magnetic susceptibility models.It is proved that the high magnetization anomaly will have a significant influence on the forward response and inversion results by theoretical model examples.The synchronous inversion has a better resolution for the high resistance and high magnetization anomaly body.The aeromagnetic method is a branch of the ground magnetic method.Based on the two-dimensional forward and inversion of the ground magnetic method,the twodimensional forward and inversion algorithm of the aeromagnetic method is developed in this paper.The Occam algorithm is used in the inversion.Different examples verify the correctness of the model.Based on the above research,this paper uses the cross gradient function to realize the mutual constraint of resistivity and susceptibility.Then we carry out joint inversion of FAEM and aeromagnetic method.In the end,we compare the results of resistivity single parameter inversion,synchronous inversion,and joint inversion through multiple model calculation examples.The results prove that joint inversion has a useful improvement in model restoration and verifying the reliability of the algorithm.