We validate two-dimensional ionospheric tomography reconstructions against EISCAT incoherent scatter radar measurements. Our tomography method is based on Bayesian statistical inversion with prior distribution given by its mean and covariance. We employ ionosonde measurements for the choice of the prior mean and covariance parameters and use the Gaussian Markov random fields as a sparse matrix ...

A double-adaptive adjustment algorithm (DAAA) is proposed to reconstruct three-dimensional ionospheric electron density (IED) distribution. In the DAAA method, relaxation factor of multiplicative algebraic reconstruction technique (MART) first adaptively adjusted by introducing adaptive MART (AMART). To avoid voxels without any rays traversing them becoming dependent on initial IED values, smoo...

Abstract The insufficient number of low-elevation observations is a limitation the three-dimensional ionospheric computer tomography (CT) based on global navigation satellite system (GNSS). To solve this problem, accurate prior information regional ionosphere must be obtained. However, it difficult to explicitly and accurately express information. This study uses compressed sensing (CS) for fir...

We apply a natural pixel (NP) decomposition to the problem of computerized ionospheric tomography (CIT). For tomography from very few angles, the NP approach provides some distinct advantages over standard basis expansions. The NP solution requires no prior assumption and as such embeds into the solution the natural spatial resolution supported by the data. For the uniquely constrained CIT geom...

many recent researches have been devoted to investigating the connection between seismic activity and ionospheric variations. it has been shown that the behavior of characteristic parameters of the ionosphere can be used as temporal and spatial precursors of strong earthquakes ( ). in the present work variations of critical frequency of ionospheric f2 layer as a temporal precursor for the qom e...