An Acoustic Tomography Of Iterative Regularization Algorithm Based On LSQR

Tomography can reconstruct objects without destroying the object, so that can help people observe the internal structure of the object, which makes the application of tomography is widely used. This article compares the currently frequently-used inversion algorithm, in order to improve the retrieval accuracy and speed of retrieval. Conducts inversion calculate on the LSQR method and Tikhnov iteration regularization method basis. It includes the following four areas:First, review the development of the inversion algorithm tomography at home and abroad, and make a simple explanation for the difficulties in the practical application of tmography techniques.Second, it introduces the mathematical basis tomography of Radon transform, Radon inversion, several ray tracing principle of the method, eikonal equation of the acoustic wave and tomography inversion method, and also introduces LSQR algorithm used the Lanczos method and Givens methods and iterative regularizetion algorithm in details.Again, use the node method to establish a velocity model, describe how to use interpolation methods to calculate the speed of cell within the grid in detail, and take the ray tracing of three different models to prove that the method is effective, and establish the inversion equation on this basis.Finally, proposed a method based on LSQR algorithm and iterative regularization algorithm. The paper describes how to select regularization factorion. Last, in order to verify the feasibility. We compare this inversion results with the LSQR algorithm inversion results and iterative regularization algorithm inversion results. The retrieval accuracy is improved for the comparison the results. So this method is feasible.