Sparse 2D-DCT Reconstruction of Total Electron Content Maps

In this paper, two-dimensional Discrete Cosine Transform analysis of total electron content (TEC)maps is investigated. It is demonstrated that most of the signal energy is contained within the low wavenumber DCT coefficients. Using this observation, maps are reconstructed, and the normalized error between the original map and the reconstructed map are calculated. It is shown that beyond a certain wavenumber, normalized error is sufficiently low and reconstructed maps are visually satisfying. Thus, TEC maps are found to be sparse in nature.