Boardsen, S. A., W. W. L. Taylor, J. L. Green, and S. F. Fung, Using
high latitude, high altitude in situ plasma wave measurements for
planning radio plasma imaging, presented at the American Geophysical
Union Spring Meeting, Baltimore, Maryland, May 20-24, 1996.

S A Boardsen, NASA GSFC/HSTX, National Space Science Data Center Code
633, Greenbelt, MD 20771 (boardsen@nssdca.gsfc.nasa.gov), W W L
Taylor, Nichols Research Corp., Arlington, VA 22209
(taylor@nssdca.gsfc.nasa.gov), J L Green, Space Science Data
Operations Office, NASA/Goddard Space Flight Center, Code 630,
Greenbelt, MD 20771 (green@nssdca.gsfc.nasa.gov), S F Fung, NASA GSFC,
Space Physics Data Facility Code 632, Greenbelt, MD 20771
(fung@nssdca.gsfc.nasa.gov)

Radio plasma imaging of the Earth's magnetosphere, including the
magnetopause and plasmapause, will yield unprecedented insight into
their real time configuration and dynamics. A Radio Plasma Imager
(RPI) is an instrument on IMAGE, a high inclination spacecraft
proposed to MIDEX (MID-sized EXplorer). The RPI is based on the same
principles as ionospheric sounders, but will have direction finding
capability and use advanced signal processing techniques to improve
the signal-to-noise ratio. RPI will operate over the frequency range
of 3 kHz to 3 MHz. It must be able to distinguish between the return
echoes and the noise background from the naturally occurring plasma
waves. Therefore it is important to determine the expected noise
background due to in situ plasma waves. In this study, Hawkeye and
DE-1 data are used to create frequency dependent plasma wave maps of
the high altitude, high latitude magnetosphere, from which the noise
background can be determined. Both Hawkeye and DE-1 were in polar
orbits with apogees of 21  and 4.67 RE respectively and they collected
4 and 3 1/2 years of plasma wave data over their mission lifetimes.
The plasma wave maps will be used to determine the expected noise
levels over the IMAGE orbit, and help determine appropriate RPI
operational modes to minimize the effect of ambient noise. A number of
calibration checks and binning techniques will be performed on the
wave data.