Computerized tomography (CT) technique has had a revolutionary impact in the field of medical diagnostic imaging and is now routinely used to produce high quality images of a section of the human body. The mathematical foundation of CT was laid as early as 1917 by Radon. The technique has also been applied to the study of ocean structures and geological formations. CT technique can be used for investigation of the vertical and horizontal structure of the ionosphere when the line integral of the parameter (e.g. electron density) is the measured data through the region of interest.In this dissertation, efforts have been made to address several issues related to the meaningful reconstruction of the ionosphere using CT technique. Efforts have also been made to investigate the electron density distribution of the low-latitude and mid-latitude ionosphere through tomographic reconstruction using the Generalized Singular Value Decomposition algorithm.