Approximation of ionosphere parameters using spherical functions

1Yankiv-Vitkovska, LM, 1Dzhuman, BB
1National University «Lviv Polytechnic», Lviv, Ukraine
Space Sci.&Technol. 2018, 24 ;(4):61-70
Publication Language: Ukrainian
Abstract: 
The use of GNSS-technologies for ionospheric monitoring allows us to provide a study of global and regional phenomena in the ionosphere practically in real time. At the present stage, the restoration of the spatial distribution of VТЕС at the local and the regional scale is demanded, especially for solving and providing coordinate tasks. The model representation allows us to execute a spatial interpolation and, in some cases, an extrapolation of the VTEC values based on the initial data about the ionosphere parameter on the system of discrete points ¾ GNSS-stations. In this article, we present a method for approximating the VTEC ionosphere parameter. We propose the system of spherical functions orthogonal on a spherical trapezium as a basic for approximating the regional field of the VTEC parameter. We substantiated the advantages of this method in comparison with the SCHA method. The used input data was the value of VTEC parameters for one epoch that was obtained after processing the data of 47 stations from the network of permanent GNSS-stations ZAKPOS. Estimation of the accuracy of the model was done. We assumed that the results obtained in this work could be applied to restore the spatial distribution of VTEC at the local and the regional scale, which is necessary for the correct solution of providing coordinate tasks.
Keywords: ionosphere, spherical functions, spherical trapezium, VTEC parameter