D.A. Rozhdestvenskiy - Post-graduate Student, Leading Engineer, JCS «Academician A.L. Mints Radiotechnical Institute», Moscow. E-mail: diieman@mail.ru, drozhdestvenskiy@rti-mints.ru
A. Yu. Perlov - Post-graduate Student, Engineer JCS «Academician A.L. Mints Radiotechnical Institute», Moscow. E-mail: karmageddon90@mail.ru; aperlov@rti-mints.ru

Irregularities of ionosphere layers cause refraction of propagating radar signals and, therefore, target azimuth and range measurements distortion. Ionospheric parameters operative estimation is required for taking into consideration ionosphere influence on radar measurements and correction of corresponding distortions. Effective technique for ionospheric parameters estimation consists in sounding by means of radio signals of satellite navigation systems (GPS, GLONASS). It includes navigation satellites pseudorange accurate measurements at two different frequencies. Dispersive difference of signal delay at this frequenciesdepends on the value of total electron content (TEC) along the line of sight from radar up to navigation satellite. This research subject consists intesting hardware and processing algorithms of two-frequencies signals in radio-navigation satellite systems intended for further radar measurements correction. Investigation problem includes ionospheric parameters measurement using two-frequency technique and creation the operative map of TEC variations in a given space sector. This map is required to provide corrections compensating ionosphere influence on radar measurements. Results obtained give accuracy estimate of TEC measurement using pseudo-range and signal phase data from GPS/GLONASS receivers at frequencies L1, L2.