Auroral electron precipitation produces both E region ionization and bremsstrahlung X rays. In a set of coordinated observations these atmospheric effects of electron precipitation were measured simultaneously by the X ray sensor on the Defense Meteorological Satellite Program F2 spacecraft and by the incoherent scatter radar at Chatanika, Alaska. In all data sets there was good agreement between the locations of the X ray source regions and the regions of enhanced E region ionization. Detailed comparisons were made between the measured and the derived altitude profiles of ionization for two auroral conditions, a premidnight auroral band and a sunlit diffuse aurora. These comparisons validate the ability to derive auroral ionization from satellite-based X ray measurements.