|
|
 |
|
|
Ann. Geophys., 19, 593-600, 2001
www.ann-geophys.net/19/593/2001/
© European Geosciences Union 2001
The MEDUSA electron and ion spectrometer and the PIA ultraviolet photometers on Astrid-2
O. Norberg1, J. D. Winningham2, H. Lauche3, W. Keith2, W. Puccio1, J. Olsen1, K. Lundin1, and J. Scherrer2
1Swedish Institute of Space Physics, Box 812, SE-981 28 Kiruna, Sweden
2Southwest Research Institute, P. O. Drawer 28510, San Antonio, Texas 78228-0510, USA
3Max-Plank-Institut für Aeronomie, Postfach 20, D-37189 Katlenburg-Lindau, Germany
Abstract. The miniature electron
and ion spectrometer MEDUSA on Astrid-2 consists of two
"top-hat"-type spherical electrostatic analyzers, sharing a common
top-hat. Fast energy sweeps (16 electron sweeps and 8 ion sweeps per second)
allow for very high temporal resolution measurements of a two-dimensional slice
of the particle distribution function. The energy range covered, is in the case
of electrons, 4 eV to 22 keV and, in the case of ions, 2 eV to 12 keV. MEDUSA
is mounted with its aperture close to the spin plane of Astrid-2, which allows
for good pitch-angle coverage when the local magnetic field is in the satellite
spin plane. The PIA-1/2 spin-scanning ultraviolet photometers measure auroral
emissions. Using the spacecraft spin and orbital motion, it is possible to
create two-dimensional images from the data. Spin-scanning photometers, such as
PIA, are low-cost, low mass alternatives to auroral imagers, but place
constraints on the satellite attitude. Data from MEDUSA are used to study
processes in the auroral region, in particular, electrodynamics of aurora and
"black aurora". MEDUSA is also a technological development, paving
the way for highly capable, miniaturized particle spectrometers.
Key words. Ionosphere (instruments
and techniques) – Magnetospheric physics (auroral phenomena; instruments and
techniques)
Full Article in PDF (902 KB) |
|
|
