A single station ionospheric empirical model using GPS-TEC observations based on nonlinear least square estimation method

Estimation Method of Ionospheric TEC Distribution using Single Frequency Measurements of GPS Signals

The satellite-to-ground communications are influenced by ionospheric plasma which varies depending on solar and geomagnetic activities as well as regions and local times. With the expansion of use of the space, continuous monitoring of the ionospheric plasma has become an important issue. In Global Positioning System (GPS), the ionospheric delay, which is proportional to ionospheric total elect...

Multiple solutions of a nonlinear reactive transport model using least square pseudo-spectral collocation method

The recognition and the calculation of all branches of solutions of the nonlinear boundary value problems is difficult obviously. The complexity of this issue goes back to the being nonlinearity of the problem. Regarding this matter, this paper considers steady state reactive transport model which does not have exact closed-form solution and discovers existence of dual or triple solutions in so...

Challenges of Real-Time Monitoring of Ionospheric Perturbations and TEC Fluctuations with GPS Single Station

Nonlinear Estimation to Assimilate GPS TEC Data into a Regional Ionosphere Model

A new method of is being developed to estimate the ionosphere’s 3-dimensional electron density distribution based on GPS slant TEC data. The goal of this effort is to develop a generalized parametric ionospheric model that is amenable to data assimilation using powerful nonlinear least-squares batch filtering techniques and related techniques. In addition to assimilating GPS TEC data, this meth...

least square estimation of the bias of the measured distance between the two grace satellites and production of a new kbrl1b-x files versions based on gps observations

gravity recovery and climate experiment (grace) satellite gravimetry mission launched in march 2002 based on its twin gravimetric satellites makes application of both high-low (hl) and law-low (ll) gravimetric techniques possible. the ll is based on satellite-to-satellite tracking (sst) via the one way two frequencies k-band-ranging between the two grace satellites. as a result of combination o...