Abstract
The two plasma experiments aboard the AFROS-B satellite determined the main plasma quantities in the height range 220-880km. These complementary instruments, a Retarding Potential Analyser and an Impedance Probe, provided the electron and ion temperatures, the main ion constitutents, the suprathermal electron flux and the plasma density.
This paper summarizes a selection of the obtained results. Comparisons of several quantities with other observations demonstrate the high reliability of the AFROS plasma data. As a contribution to sensor theory a dependence of RPA measurements on the magnetic field vector has been established. The ion temperature and composition turn out to undergo a strong latitudinal variation, the highest hydrogen concentration in the upper atmosphere being located at ±20° latitude. Concerning the longitudinal variation of electron density discrepancies between measured data and existing models have been revealed. The statistical relation between the position of the mid-latitude trough and magnetic activity was studied for a fixed local time. First results of a synoptic study of the high latitude day-side ionosphere using AFROS-B and ISIS-II data are presented.
