TOMOGRAPHIC RECONSTRUCTION OF IONOSPHERIC ELECTRON-DENSITY WITH EUROPEAN INCOHERENT-SCATTER RADAR VERIFICATION

A campaign was conducted in late September 1991 to obtain experimental measurements for use in ionospheric tomography. Four stations receivi ng signals from the Navy Navigation Satellite System satellites were s et up in a meridional chain in Scandinavia covering some 10-degrees of latitude. Measurements of total electron content were made for six sa tellite passes over a 2-day period coinciding with an extended run of the CP3f latitudinal scan common program of the European incoherent sc atter radar. A new reconstruction technique involving the use of two-d imensional basis vectors has been used to convert the total electron c ontent measurements to images of electron density in a height versus l atitude plane. Comparisons of the tomographic images and the independe nt measurements of electron density from the radar show good general a greement. Broadly similar troughs and enhancements are observed by the two techniques, and a latitudinal gradient in the height of the peak density is reproduced in both data sets.