Application of Ionospheric Topside-Sounding Results to Magnetospheric Physics 
and Astrophysics

Robert F. Benson
Laboratory for Extraterrestrial Physics
NASA/Goddard Space Flight Center
Greenbelt, Maryland 20771 USA

Vladimir A. Osherovich
Laboratory for Extraterrestrial Physics
L3 CAC/Goddard Space Flight Center
Greenbelt, Maryland 20771 USA


A brief review is presented to illustrate how the knowledge and experience
gained from investigations of ionospheric topside-sounder ionograms has
benefited scientific research beyond the ionosphere. In particular, to
the interpretation of (1) natural radio emissions from space plasmas,
(2) sounder-stimulated echoes and plasma emissions, and plasma diagnostics
in planetary magnetospheres and (3) X-ray spectra of disks around neutron
stars and black holes. The relevant data are from sixty satellite-years of
ionospheric topside-sounder operations by the four satellites of the
International Satellites for Ionospheric Studies (ISIS) program from 1963
through 1989. Not all of these data were reduced to ionograms on 35-mm
film. An ongoing effort at the NASA/Goddard Space Flight Center is
producing digital topside-sounder ionograms directly from a selected
subset of the original telemetry tapes. More than 300,000 digital
ionograms are now in the National Space Science Data Center at the
NASA/GSFC (http://nssdc.gsfc.nasa.gov/space/isis/isis-status.html).

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Proceedings of the Ionospheric Effects Symposium, Alexandria, VA, 2002.