engleski

Local model of quiet space weather GPS ionospheric delay for the area of Northern Adriatic

Satellite system position accuracy primarily depends on conditions in space between the satellite vehicles and ground receivers, namely at heights up to 2000 km above the surface of the Earth. Solar activity accumulates the free electrons and ions of various elements (oxygen and nitrogen mostly), slowing the signal propagation speed and degrading positional accuracy. Exploring the ionosphere and its influence to satellite positioning, various correction models have been developed, in order to predict and to correct position error caused by the ionospheric delay. The most common model is Standard GPS Ionospheric Delay Model. The parametres of the model are incorporated in the navigational message, which is then sent from the satellites to receivers on Earth. Those parametres are used in the position calculation procedure. Given that Standard Model operates on global basis, it does not take into account local patterns of ionospheric dynamics for the specific point on the globe. In this case, the position derived by the satellites becomes additionaly inaccurate. The elaborated data show the instances when daily pattern of ionospheric delay does not follow Standard model and thus does not correct the ionospheric error component. The paper processes daily ionospheric dynamics from the reference station placed in the area of Northern Adriatic for the year 2006. This local pattern appears through entire year and it is correlated with quiet to unsettled Space Weather conditions. Compiling the several day period, the new, local model is proposed, mathematically describing the observations.

Standard Model; Space Weather; Ionosphere; Ionospheric error; Local Model

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