Tomographic imaging of ionospheric distributions

The development of a new tomographic imaging system for characterizing the electron density distribution in the ionosphere has generated considerable interest within both the ionospheric physics and satellite communications fields. Significant irregularities occur in these distributions which can severely affect signals propagating through or reflecting off of the ionosphere. Ionospheric tomography enables two-dimensional reconstruction of these distributions in vertical slices of the ionosphere. The configuration of the data acquisition system, however, limits the information content of the data and causes resolution degradation in the reconstructed images. Two algorithms have been developed which incorporate a priori information for resolution enhancement the orthogonal decomposition algorithm and the direct Fourier method with bi-directional extrapolation