A COMPARISON OF IONIZATION DENSITIES DETERMINED FROM SPACECRAFT AND INCOHERENT-SCATTER RADAR DATA

By comparing direct measurements taken from onboard Atmosphere Explore r spacecraft (AE), in eccentric orbit, with incoherent scatter radar ( ISR) measurements taken from the ground, we illustrate both the merits and the difficulties involved in such comparisons. Five altitude prof iles of ionization determined from AE, in near coincidence with ground stations making ISR measurements, compared favorably with the ISR dat a so long as the AE measurements were properly analyzed for the effect s of variations in latitude and solar zenith angle along the spacecraf t orbit. Copyright (C) 1996 Elsevier Science Ltd