Abstract:We developed a system for monitoring the ionosphere, which uses the GNSS network located in the western part of Ukraine. The system is based on determining the ionosphere parameters from GNSS observations performed at an individual station. We are proposed algorithm for restoring the spatial position of the ionospheric state or its ionization field according to the regular definitions of the TEC parameter. The description below shows one of the possible solutions that are based on the application of the regularized approximation of functions with numerous variables. To experimentally determine the changes in the ionization field in time, we took measurements from 272 days in 2013 that were determined during the GNSS observations at 17 continuously operating stations of the ZAKPOS network. The resulting error indicators show that the developed algorithm gives consistent results for ionization field restoration that do not depend on the ionosphere state, satellites positions and changes in number of stations in the network used for computations.