BASIC TOMO: an educational tool for investigating the role of controlling parameters and observation geometry in tomography problems

The paper presents an educational version of the tomography algorithm BASIC TOMO, which is aimed at demonstration of the role of different controlling parameters in inversion. The algorithm uses a simplified approximation of rays with straight lines and a model parameterization with the use of rectangular cells. The tomography procedure is reduced to solving a system of linear equations, which is performed using the LSQR method. This study presents several exercises showing the role of different factors in inversion, such as grid spacing, smoothing, ray configuration, and noise in the data. The calculations are performed for different types of synthetic models. All the results can be easily reproduced using the appended version of the BASIC TOMO code.