Ionospheric tomography is a method to investigate the ionospheric electron density in two or three dimensions. In this study, the function-based tomographic technique has been used for regional reconstruction of a 3D tomographic model of the ionospheric electron density using the GPS measurements of the Iranian Permanent GPS Network. Two-dimensional Haar wavelets and empirical orthogonal functi...

ith the transition to the Global Positioning System, Transit has been decommissioned, after having served well for the Fleet. A new system, the Navy Ionospheric Monitoring System, was established using Transit satellites. This article examines the application of the new system to the field of computerized ionospheric tomography. (

We develop the formalism for a PIM-based functional for stochastic tomography with a Kalman filter, in which the inversion problem associated with four-dimensional ionospheric stochastic tomography is regularized. For consistency, GPS data is used to select dynamically the best PIM parameters, in a 3DVAR fashion. We demonstrate the ingestion of GPS (IGS and GPS/MET) data into a parameterized io...

The most demanding application of wide area di erential corrections to GPS is vertical positioning of aircraft on precision approach. Here the Wide Area Augmentation System (WAAS) combines accuracy requirements on the order of ones of meters with safety of life integrity requirements which specify that any vertical position errors greater than the Vertical Protection Limit be enunciated to the ...

The ionosphere affects the electromagnetic waves that pass through it by inducing an additional transmission time delay. The ionosphere influence has now become the largest error source in GPS positioning and navigation after the turn-off of the Selective Availability (SA). In this paper, methods of 2D gridbased and 3D tomography-based ionospheric modeling are developed based on regional GPS re...

Ionospheric tomography using GPS data has been reported in the literature and even the application to radar altimeter calibration was succesfully carried out in a recent work ( [1]). We here present a new software tool, called Global Ionospheric Stochastic Tomography software (GIST), and its powerful capability for ingesting GPS data from different sources (ground stations, receivers on board L...

We develop a minimization functional in order to regularize the inverse problem associated with three-dimensional ionospheric stochastic tomography. This functional is designed to yield, upon minimization, a solution which maximizes the frequency content of the solution below a certain cutoo, while keeping 2 constant. We show how this functional can be rewritten in terms of the correlation func...

Nowadays GPS is widely used to monitor the ionosphere. However, the current results from ground-based GPS observations only provide some information on the horizontal structure of the ionosphere, and are extremely restricted in mapping its vertical structure. In this paper, tomography reconstruction technique was used to image 3D ionospheric structure with ground-based GPS. The first result of ...