The Research Of Inverse Scattering Imaging Algorithm In Microwave Nondestructive Testing

The algorithm of microwave imaging plays an essential role in MNDT. The main work of this paper is the research of microwave imaging algorithm, and the imaging of concrete media column.The electromagnetic scattering is a foundation of the algorithm of microwave imaging, and also one of the important contents of the electromagnetic theoretical research. Through understanding the solving mode, several widely used numerical computing approaches of the electromagnetic scattering as well as the characteristics are studied. The step of the analysis process in ANSYS working environment is introduced. Finite element models are built according to the task in ANSYS. In order to reduce the size of the computational domain, perfectly matched layers are used. Parallel plate waveguide is loaded to transmit TEM, work frequency is 3.0 GHz. After simulations are performed, the data of simulation are used as the results of electromagnetic scattering.Microwave imaging is also the electromagnetic inverse scattering which reconstructs the inner structure of target can get relevant information that people are interested in without keeping in touch and destroying the scattering body, and has extremely rich practical value, so the masses of microwave workers keep being devoted to the research of the high-efficient, accurate reconstruction algorithm. Many algorithms of microwave imaging have been developed and have been utilized already. Finally, on the basis of introduced algorithms, adopt an iterative algorithm which the scattering parts are based on finite element numerical calculation method, the inverse scattering parts use the equivalence principle and variation principle. In accordance with the ANSYS modeling and mesh, imaging region is separated in to small grids. Then the objective function is seemed as a matrix which each element with a small mesh of nodes. This algorithm can be applied in the matrix computation, with the MATLAB programming. Through simulation, the effectiveness of the concrete media column imaging is certificated. In the end, in the same simulation conditions, using the spectral domainω-k imaging algorithm for imaging the same model. Two algorithms are compared, and the superiority of the new algorithm in this paper is preliminarily certificated.