А.V. Grebennikov, F.V. Zander, I.N. Sushkin

Recently on the basis of use of satellite navigation systems of GLONASS and GPS are received, connected with registration of harbingers of earthquakes in Earth ionosphere. In article the algorithm of existential processing of an assessment of the total electronic contents (TEC) in an ionosphere on the basis of measurements of time of distribution of a radio signal from the navigation satellite to navigation equipment of the user is considered. Temporary dependences of the total electronic contents in an ionosphere contain the low-frequency oscillatory component caused by the meteorological phenomena, including the geomagnetic fluctuations caused by flashes on the Sun, a high-frequency component of the fluctuations, caused by not uniformity in an ionosphere, including radon emission on the threshold of earthquake and a noise component of a variation of TEC caused by noise of a measuring instrument (navigation equipment of the user). For definition of algorithm of existential processing it is considered alarm a component of cross correlation function of measurement of the total electronic contents and a basic signal. As experimental data in article results of an assessment of the total electronic contents are given in an ionosphere of Earth made on measurements of a global network of IGS stations (International GNSS Service) consisting of stationary two-frequency GPS receivers. Schedules of a variation of TEC are provided in the day and night period of time, in regions of seismic activity from which it is visible that during the night period of time ionospheric indignation in 2-4 days prior to earthquake is most brightly expressed. Thus peak value of TEC, during the night period of time, can exceed in 1,5 times of its average value, whereas during the day period of time in 1,3 times. The presented three-dimensional schedules of measurement of TEC showed that the area of localization of ionospheric indignations, in seismic activity, makes about 500 km. In the table provided in article, 8 strongest are considered earthquakes for the last 3 years on which authors it was possible to receive results of measurements of a global network of GPS stations. The given factor of ionospheric indignation defined as the relation of the maximum value of the total electronic contents to average value of TEC three days prior to abnormal splash, changes during the day period of time in a range from 1,15 to 1,37, and during the night period of time in a range 1,4-1,6.