JEM-GLIMS Mission ( Global Lightning and sprIte MeasurementS on JEM-EF )

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JEM-GLIMS Mission( Global Lightning and sprIte
MeasurementS on JEM-EF )
TLE Workshop, Corte, June 26 2008
M. Sato (Hokkaido Univ.), Y. Takahashi(Tohoku
Univ.), S. Watanabe (Hokkaido Univ.) T. Ushio
PI, T. Morimoto, Z-I. Kawasaki (Osaka Univ.) M.
Suzuki, T. Takashima(ISAS/JAXA) H. Ohya, H.
Nakata (Chiba Univ.), K. Odo (Gifu Univ.), Y.
Hiraki, T. Adachi(Kyoto Univ.), Y.
Hobara(Tsuyama Technical College)
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TLEs

• Discovered in 1990s
• Associated with cloud-to-ground discharges

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Generation Mechanism

• Can QE mode explain following observational
  results?
• Low charge moments (several hundreds of C?km) of
  the parent CG
• (b) Displacement between the sprite location and
  CG location (max. 50km)
• (c) Time delay between the parent CG and sprites
  (gt100 ms)
• (d) Different type of sprites (column, carrot)
• (e) Number of column

QE Model
Ambient electrons are accelerated by the QE
field, and cause the conventional air break down.
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Generation Mechanism
Figs. Relationship between the initiation of
sprites and the onset of ELF/VLF perturbations.
Ohkubo et al., 2005
Figs. Horizontal lightning current plays crucial
role. Valdivia et al., 1997
Horizontal lightning current
? Nadir observation ? Horizontal distribution of
sprites
Figs. Correlation between number of columns and
peak current Adachi et al., 2004
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Generation Mechanism
Horizontal distribution of columniform sprite is
like Milk Crown !!
Triangulation of sprite occurrence location by
amateur astronomer.
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TGFs
TGF and Lightning

• TGF observation by RHESSI
• gt 700 TGF events
• Rate 1 event / 2 days or more?
• Association with lightning

Runaway electrons
Smith et al. 2005

• which discharge process?
• association with TLEs?

Bremsstrahlung
Simultaneous observation of TGFs and lightning
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Science Goal of JEM-GLIMS
Lightning, TLEs and TGF observation from
JEM-EF/ISS.

• Global survey of TLEs and TGFs
• ? occurrence rates distributions
• Nadir observation of TLEs
• ? relationship between sprites
• and lightning horizontal currents
• Simultaneous observation of lightning, TLEs,
  TGFs (with ASIM)
• ? generation mechanism of TGFs

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Scientific targets summary Sprite-Sat (nadir
imaging TGF/Lightning detection) Lightnin
g development by VHF Spectroscopy (300-430 nm)
by GRISM spectro-imager
Coordinated collaborative measurements with
ASIM/TARANIS is strongly recommended.
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International Space Station (ISS)
JEM
Port-sharing experiment module
JEM-EF
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Scientific Instruments heritage
CMOS cameras Sprite-Sat
(LSI)Photometers TARANIS (MCP-PH) VHF
interferometer SOHLA-1 GRISM spectroimager
VLF receiver Sprite-Sat (VLF)
total funding (2 M USD?) and time for
developments is so limitedwe need to make use
of recent heritages.
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JEM-GLIMS
Energy transfer from lower atmosphere to the
upper atmosphere
Spectroimager
Photometers
CMOS camera
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CMOS Cameras

• CMOS 1 (for lightning detection)
• ? 740-830 nm
• OI 777.4 nm
• NI 744.2 nm, 822.3 nm
• CMOS 2 (for sprite detection)
• ? 762 /- 5 nm
• ? strong sprite emission
• N2 1P
• ? absorbed by O2 (lightning emission)

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CMOS Sensor

• CMOS Sensor
• STAR-250
• Wavelength 200-1000 nm
• QE 35 max
• Sensitivity 0.15 A/W _at_762nm
• Lens
• CCTV lens
• Moritex ML-2514
• Heritage of CMOS camera development for
  SPRITE-SAT
• Reduction of the development cost and time.

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CMOS Camera for SPRITE-SAT
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CMOS Camera for SPRITE-SAT
ltCMOS Cameragt x2 ? 762nm, 740-830nm FOV
40 Optics F1.4, f25mm Detector
STAR-250 pixel number 512 x 512 sensitivity 6.9
E-6 W/m2 for sprite resolution 10 bit
Fig. CMOS Camera for SPRITE-SAT
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Photometers
Helitage TARANIS MCP-PH

• 4 photometers
• 2 of 4 photometers will
• be operated

PH size (X, Y, Z) (140, 115, 185)
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Photometers
FOV42.7? Lens
ltPhotometergt x4 ? 150-280 nm 337 /-10 nm
762 /-10 nm 600-800 nm FOV 42.7?,
86.8? detector PMT PDD Optics F1.50,
?15mm F1.72, ?6mm Sensitivity 10
nW/m2 Time res. 10 ?s
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GRISM Spectroimager
ltGRISM spectroimagergt x1 ? 300-430nm FOV
40 wavelength res. 2nm detector E2V CCD
(80x80 pixels) time res. 2ms
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VHF Interferometer
ltVHF interferometergt x2 Antenna patch-type
antenna freq. range 30-100 MHz directivity
Nadir 30 amp. gain 45 dB sampling freq.
200MHz A/D res. 8 bit
Fig. VHF electronics onboard the SOHLA-1
satellite.
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VHF Interferometer
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VHF Interferometer
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Organization
Coop. Org. JAXAISAS M. Suzuki
PI T. Ushio(Osaka Univ.)
Science Group
Photometer, CMOS camera, M. Sato (Hokkaido
Univ.), Y. Takahashi (Tohoku Univ.) S. Watanabe
(Hokkaido Univ.) ,T. Adachi, Y. Hiraki Y.
Hobara,
GRISM spectroimager M. Suzuki(JAXA), M.
Sato(Hokkaido Univ. ), T. Adachi, Y. Hobara
VHF interferometer T. Morimoto, T. Ushio, Z-I.
Kawasaki (Osaka Univ.),, H. Oya, H. Nakada
VLF Y. Takahashi, U. Inan
CPU M. Suzuki, T. Takashima (ISAS/JAXA)
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Master Schedule
Launch 2011
We are here!
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Cooperative Obs.
ASIM
2012- Polar orbit 700 km Optical gamma-ray
detector Nadir Obs.
2012- Inclination 51deg Optical gamma-ray
detector Nadir Lim Obs.