Diogonosis of quasi-wave disturbances in near-earth plasma by modified SSA method

This paper presents a modified SSA (Singular Spectrum Analysis) method, intended for the analysis of weak quasi-wave perturbations of the plasma density in the topside ionosphere. Its special feature is the transformation of the original series of the latitudinal distribution of the electron density at a fixed height in the new series. This is achieved by removing trend from the original series and subsequent double differentiation of the residue. This procedure pursues two purposes. The first purpose is elimination of the constant and linear components in the residue of trend. The second aim is the providing of higher contrast manifestation of the harmonic component in a new series. The method was verified on test calculations and real experimental data and has showed a high resolution.