Commission H (Waves in
Plasmas) Activity Report
Y. Omura, T. Okada, and H. Matsumoto
1.
Research Project
(R-1)
NOZOMI
The Mars
exploring spacecraft Nozomi which ISAS launched in
1998 is currently in a cruising orbit with the Mars orbit injection scheduled
for early January 2004. The science instruments onboard Nozomi originally intended for the science observation in
Mars orbit have been conducting some observation in the cruising orbit resulting
in very fruitful rewards. On April 26(JST) we found a problem with part of
communication and attitude control systems and all the science observations have
since been suspended. The most likely cause might be due to impact of high
energy particles from the sun during CME event accompany with the X1.5 class
solar flare starting on April 21 which could have caused a problem with part of
the power system onboard Nozomi. We are now in the
process of identifying the details of the problem and the way for recovery, but
it could take up to 6 months or so. During this period, no science observation
will be conducted.
(R-2)
GEOTAIL
The GEOTAIL spacecraft has been operated
without any major troubles. The spacecraft is expected to be in a good condition
at least until the next long eclipse in 2003.
(R-3)
EXOS-D
The EXOS-D (Akebono) spacecraft has attained
the 13 years of successful operation without any major troubles. The regular
data acquisition is continued at stations in
(R-4) Polar
Patrol Balloon (PPB) experiment in
National Institute of Polar Research (NIPR) will carry out long-duration
balloon experiment in
(R-5) ELF
wave observation at Syowa station,
ELF magnetic field observations in the
frequency range of 1-500 Hz have been carried out at Syowa station since
February 2000, using two horizontal search coil magnetometers. Good waveform of ELF transients were observed in correspondence
with sprites and elves identified in the northern
hemisphere.
(R-6) Lunar
Radar Sounder experiment on-board SELENE spacecraft
The Lunar Radar Sounder (LRS) experiment
on-board the SELENE will provide subsurface stratification and tectonic features
in the shallow part (several km depth) of the lunar
crust, by using an FM/CW radar technique in HF frequency range. Knowledge of the
subsurface structure is crucial to better understanding not only of the geologic
history of the moon, but also of the regional and global thermal history of the
Moon, and also of the origin of the Earth-Moon system. In addition to the
subsurface radar experiment, LRS will provide the spectrum of plasma waves, and
solar and planetary radio waves in wide frequency range covering from 10 Hz to
30 MHz. The SELENE spacecraft will be launched in 2005.
(R-7) Wave Form Capture onboard the SELENE
spacecraft
This receiver is a part of the lunar radar
sounder (LRS) and is composed of two types of digital receivers, a digital sweep
frequency analyzer which covers from 1kHz to 1MHz and a wave form receiver which
covers from 100 Hz to 100 kHz. In
the former, the A/D converted signal is converted into a narrow band signal by a
programmable down converter (PDC) and its frequency spectrum is obtained by the
FFT. Spectra of the whole frequency range are obtained by sweeping the center
frequencies of the converted signal. The latter, the A/D converted data are
transmitted efficiently by the data compression. This will observe plasma waves
in the magnetosphere and the solar wind at the lunar distance and wave phenomena
in the lunar wake.
(R-8)
In order to promote and help students and
young engineers to learn the space science and technology, a working group named
as Society of Alaska Rocket Project has been built up in SGEPPS (the Society of
Geomagnetism and Earth, Planetary and Space Science). In order to measure the
electron density in the ionosphere in the altitude lower than 70 km which are
not clear in the IRI model, the ARP members and ASRP (Alaska Student Rocket
Project) members in Alaska launched the SRP-4 rocket carrying an electron DC
probe and a radio receiver to observe the LF air-plane navigation wave and AM
broadcasting waves. Full wave analysis using data by the rocket experiment and
MF radar, the electron density profile at altitude 50-70km was made clear which
is different from the IRI model.
2.
Past Meetings
l
The 4th YRP Symposium on
Cooperation between Industry, Academia and Government, Yokosuka Telecom Research Park, Kanagawa, Japan, 10-11 July
2002.
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COSPAR Colloquium gFrontiers
of Magnetospheric Plasma Physicsh, Institute of Space
and Astronautical Science,
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The 26th NIPR Symposium,
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The 27th General Assembly of
the International
l
2002 Joint Conference of
Hokuriku Chapters of Electrical Societies,
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The
Second Korea-Japan-China Joint Workshop on Space Weather,
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34th
COSPAR Scientific Assembly(2nd World Space Congress)
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The 46th Space Sciences and
Technology Conference, Communications Research Laboratory,
3. Future
Meetings
l
The 112th General Assembly
of Society of Geomagnetism and Earth, Planetary and Space Sciences, The
University of Electro-Communications, Tokyo, Japan, 11-14 November
2002.
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AGU 2002 Fall Meeting, San
Francisco U.S.A., 6-10 December 2002.
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IUGG 2003,