Use of total electron content maps for analysis of spatial-temporal structures of the ionosphere

The main aspects of a methodology for determining the total electron content (TEC) of the ionosphere from GPS observations and the principles of using two-frequency measurements of satellite signal delays in navigation systems are presented. The method developed and used at the Western Department of Pushkov Institute of Terrestrial Magnetism, Ionosphere, and Radio Waves Propagation, RAS enables to determine the absolute values of the TEC and monitor the diurnal behavior of this quantity for individual monitoring stations. The methodology for obtaining information on the spatial distribution of TEC maps of the ionosphere on the basis of an algorithm for multi-station processing of GPS observations. Using a set of algorithms and programs, regional TEC maps with a spatial resolution of 1 and a time resolution of 15 min-1 h are regularly drawn. This precision allows using TEC maps for studying the structure and dynamics of the ionosphere during different geophysical events. The results of studies of the response of the ionosphere to the solar eclipse on November 3, 2005 and the geomagnetic storms on January 22, 2012.