Improved Damped Least Squares Tomograph Algorithms And Analysis Of Influencing Fators

As the development of computer technology, Computer Tomography (CT) has been asignificant improved, which has been widely used in the medical field firstly. Acoustictomography technology can precisely and integrally simulate the physical parameters ofthe detected object. In engineering, because of its advantages such as without damaging,convenient and low costing, the technology can be widely used in engineering exploration,geological structure probing, resource exploration, seismic exploration, engineeringquality testing and so on. The technology is still under research. The main problem is howto improve the efficiency and accuracy of the imaging, which is the main content of thispaper.Firstly, this paper introduces the scientific significance and application prospects oftomography, and reviews the historical and present situation of the technology at homeand abroad, and lists the main problems of the technology. Besides, this paper presents thebasic theory and steps of tomography of tomography specificallySecondly, based on the low efficiency of the global-scan ray tracing and theideological of dichotomy searching, the paper proposes dichotomy ray tracing technology,which gives the initial incident angle of ray tracing and according to the tracking resultsthis paper uses the ideological of dichotomy to adjust the angle of incidence for the nexttracking. As the tracking result meets the given conditions the researching is stopped.Then, this paper gives the results of numerical simulation of given medium models, whichshow that the dichotomy ray tracing can effectively improve the tracking efficiency.Thirdly, this paper improves the traditional damped least squares tomographyalgorithm, which uses prior information as the internal constraint conditions in the processof damped least squares method tomography to avoid the emergence of the secondaryerror. Then this paper presents the results of numerical simulation of given mediummodels, which show that the improved damping least squares tomography algorithm caneffectively improve the accuracy of the imaging.Finally, this paper studies the influencing factors of tomography (such as the size of grid, the selection of the initial velocity model, velocity constraint restrictions and so on).This paper gives the results of numerical simulation of given medium models withdifferent parameters of influencing factors, and then compares the simulation results, lastproposes the selecting principle of influencing factors’ parameters in tomography.