Fok, M. C., J. D. Perez, R. W. Spiro, and T. E. Moore, Neutral Atom
Imaging of a Documented Storm, presented at the American Geophysical
Union Fall Meeting, San Francisco, December 15-19, 1996.

Neutral Atom Imaging of a Documented Storm

M. C. Fok (Universities Space Research Association, NASA/MSFC, ES 83,
Huntsville, AL  35812; tel:  205-544-2971; e-mail:  fok@msfc.nasa.gov)
J. D. Perez (Department of Physics, Auburn University, Auburn, AL 
36849; tel:  334-844-4264; e-mail:  perez@physics.auburn.edu)
R. W. Spiro (Space Physics & Astronomy Department, Rice University,
Houston, TX  77005; tel:  713-527-8750, ext. 3591, e-mail: 
spiro@alfven.rice.edu)
T. E. Moore (Space Sciences Laboratory, NASA/MSFC, ES 83, Huntsville,
AL  35812; tel:  205-544-7633; e-mail:  t.e.moore@msfc.nasa.gov)

IMAGE (Imager for Magnetopause-to-Aurora Global Exploration) is the
first magnetospheric mission to use the energetic neutral atom (ENA)
imaging technique to study the Earth's ring current.  During the
period of pre-launch development, it is important to simulate ENA
images that the instruments would see, under both quiet and active
geomagnetic conditions.  The October 18-20, 1995 magnetic cloud event
is chosen for study to serve this purpose.  A 3D ring current model,
with electric potential distribution and boundary ion fluxes specified
by the Magnetospheric Specification and Forecast Model, is used to
model energetic ion dynamics during this event.  Corresponding ENA
fluxes and instrument count rates are generated according to the
instrument parameters of the neutral particle detectors (HENA and
MENA) on IMAGE.  A time sequence of images and count rates will be
shown along the spacecraft orbit.  In order to determine how much ring
current intensity and pitch angle information can be obtained from
this imaging technique, the simulated ENA images will be deconvolved
and compared with the original ion fluxes produced by the ring current
model.