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

The main aspects of a methodology developed and used at the Western Department IZMIRAN 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 methodology for obtaining of TEC maps of the ionosphere is based of an algorithm for multistation 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 hr 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 January 4, 2011 and the geomagnetic storms on January 22, 2012 are presented.