MCP instrument Microcameras and Photometers

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MCP instrumentMicrocameras and Photometers

• E. Blanc, T. Farges
• CEA/DASE Bruyeres le Chatel, France
• Y. Takahashi1, M. Sato1, M. Suzuki2
• 1 Tohoku university,
• 2 JAXA/ISAS, Japan

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TARANIS MCP images and waveforms measurement
goals

• Provide unambiguously the identification, dating
  and localization of TLEs
• (sprites, elves, halos)
• TLE characterization
• global mapping, occurrence rate
• interpretation of all other instruments
• Provide dating and localization of lightning
• characterization of parent lightning
• global mapping, distance lightning-TLE
• source mechanisms
• Provide spectroscopic information (FUV/ UV /IR
  emission band)
• source mechanisms
• energy determination
• Transmit a trigger information to all Taranis
  instruments when a TLE is detected

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MCP instrument Principe
Photometers TLE and lightning wave forms
Microcameras TLE and lightning images

• TLE characterization and localizationfrom nadir
  in absorption band of the atmosphere
• Lightning localization
• - Monitoring
• - Identification of lightning contribution in the
  TLE images

• Characterization of TLEs and lightning in the
  time
• Spectroscopy in 3 different TLE emission bands
• Lightning monitoring in a large FOV
• Real time alert of TLE
  

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Spectral band selection
Observation bands selected for only Nadir
observations

• ?TLE camera and photometer in NIR 761 nm
• Strong emissions in the N2 1P band
• Encouraging results with LSO for sprite
  identification
• ?Lightning camera and photometer 600-800 nm
• Strong response expected
• ?TLE photometer in UV 337 nm
• Emission in the N2 2P band, most intense in blue
  and UV
• Needed for spectroscopy comparison IR and UV
• ?TLE photometer in far UV 150- 280 nm
• Emission in N2 LBH band of far UV (observed by
  ISUAL)
• Needed for spectroscopy
• Important for triggering (low rate of false
  alarms)

Sprite spectrum at source
N2 (0,0) 2P
N2 (3,1) 1P
762.7 nm
337 nm
N2 2P
N2 1P
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Change from phase A 4 photometers
Phase B
Phase A
Advantages TLE spectroscopy - same FOV of
PH3, PH1, PH2 Triggering of TLE in FUV - lower
false alarm rate Lightning monitoring - in a
large FOV (comparable with other instrument) -
continuous survey mode - observations over SAA
and triggering - same observation band as
lightning camera (TLE/lightning differentiation)
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Change from phase A PH sampling frequency
FUV (LBH)
UV (N2 2P)
Blue (N2 1N)
red-NIR (N2 1P)
Lightning band
UV-blue (N2 2P and N2 1N)
ISUAL, Mende et al., 2006 Takahashi, 2007
Advantages Better separation of lightning and
TLEs
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Change from phase A frame rate of the cameras
Mende et al., 2006
Continuous illumination of lightning
A continuous lightning illumination lasting 100
ms produce a strong noise in the images which can
be reduced by short integration time (30 ms
rather than 100 ms)
Advantage Better contrast ? better direct
identification of events
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Constraints

• Satellite
• Accommodation with Nadir pointing
• Field of view
• MC1, MC2 55
• PH1, PH2, PH3 55
• PH4 100
• TLE and lightning localisation
• Earth pointing with an accuracy better than 0.5
• Attitude restitution better than 0.1
• Geometrical model better than 0.1 on all pixels
  of the field of view
• Satellite stability of 0.1/s
• Stability lt 0.03 over 250 ms
• Time Precision
• 50 µs relative, 1 ms absolute
• Night observation only

Number of day without observation
60
3 LT
1 LT
40
4 LT
20
geographic latitude
0

-60
Janv
Jul
Dec
MCP latitude coverage during a year for
different satellite local time
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Archiving modes
Day time
Night time
MC1,2
PH1,2,3
PH4
Time 1 orbit
Event mode
Survey event
Triggering instrument
Continuous survey mode
400x400 pixels instead of 512x512
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Archiving modes
depending on compression methods (the most
efficient is windowing)
Voss et al, 1998
Example of survey mode with a photometer
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Camera and photometer characteristics
photometer
camera
analyzers
Changes since PRR phase A review
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Work to be done in phase B

• Reorganization of the instrument team
• CNES instrument technical responsible
• CEA MCP Needs Requirement, CMS software
• Phase B tasks Instrumentation - engineering
  model- interface definition technical
  specifications and verification plans
• Cameras and analyzer subcontracting
  invitation to tender, choice of manufacturers
• Photometers Phase B (Japan)
• Phase B tasks Simulations (CEA)
• Based on modeling and ground based
  experimentations
• Test of different instrument functions