The DEMETER satellite: Payload, Operations and Data

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The DEMETER satellite Payload, Operations and
Data

• M. Parrot
• LPC2E/CNRS
• 3A, Avenue de la Recherche
• 45071 Orléans cedex 2,
• France
• E-mail mparrot_at_cnrs-orleans.fr

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Outlines The Project The hypotheses about
the seismo EM effect Observations during seismic
activities Statistical analysis Conclusions
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The Project The DEMETER micro-satellite has been
launched on June 29, 2004 by a Dnepr rocket from
Baïkonour. The plate-form is under the CNES
responsibility and the scientific payload was
provided by scientific laboratories.
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The scientific objectives The scientific
objectives of the DEMETER micro-satellite are
related to the study of ionospheric perturbations
in relation with the seismic and volcanic
activities.
These perturbations are interesting because they
can be considered as short-term precursors
(they occur between a few hours and a few days
before a quake). The same payload will allow to
survey the ionospheric perturbations in relation
with man-made activities.
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• The scientific payload
• The scientific payload of the DEMETER
  micro-satellite has several experiments
• A set of electric sensors to measure the 3
  components of the electric field from DC to 3.5
  MHz (CETP),

• A three orthogonal search coil magnetometer to
  measure the magnetic field from a few Hz up to 20
  kHz (LPCE),
• Two Langmuir probes to measure the density and
  the temperature of the electrons (ESTEC),
• An ion spectrometer to measure ion composition
  (CETP),
• An energetic particle analyzer (CESR).

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• Measured Parameters
• Frequency range, B 10 Hz - 20 kHz
• Frequency range, E DC 3.5 MHz
• Sensibility B 1. 10-5 nT Hz-1/2 at 1 kHz
• Sensibility E 0.2 µV Hz-1/2 at 500 kHz
• Particles electrons 60 keV 600 keV
• Ionic density 5 102 - 5 106 ions/cm3
• Ionic temperature 1000 K - 5000 K
• Ionic composition H, He, O
• Electron density 102 - 5 106 cm-3
• Electron temperature 500 K - 3000 K

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The operations The orbit of DEMETER is polar,
circular with an altitude of 710 km. DEMETER
record data in two modes a survey mode all
around the Earth with low resolution, and a burst
mode with high resolution above main seismic
zones. The seismic parameters received from IPGP
are merged with the orbital parameters in a
special file of events.
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The wave experiment

• NEURAL NETWORK
• number of whistlers and dispersion.
• BURST MODE
• waveforms of 3 electric components up to 15 Hz,
• waveforms of 6 components of the EM field up to
  1.25 kHz,
• waveforms of 2 components (1B 1E) up to 20 kHz,
• spectra of one electric component up to 3.5 MHz,
• spectra of 2 components (1B 1E) up to 20 kHz,
• waveforms of one electric component up to 3.5 MHz
  (snapshots).
• SURVEY MODE
• waveforms of 3 electric components up to 15 Hz,
• spectra of 2 components (1B 1E) up to 20 kHz,
• spectra of one electric component up to 3.5 MHz.

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The DEMETER mission center
CNES
ANCILLARY DATA - Orbit Parameters - TM
station Pass-Planning - Events (orbit,
satellite) - Attitude - HK
CONTROL CENTER
OPERATION COORDINATION GROUP
Science PL TM packets
Science PL TM packets  back-up 
PL TC PLAN
LPCE (MC)
SEISMIC DATA
DEMETER DATA ACQUISITION
IPGP
TM
SCIENCE PL PROGRAMMATION GENERATION
QUICK-LOOK PROCESSING L0'
Memory handling BURST zones
Calibration validation
SCIENTIFIC USERS
OPERATION BOARD
PL status
Science operation coordination
PL and MC events
Instrument configuration
LPCE (IMSC, RNF, BANT)
CETP (IAP, ICE)
DEMETER MISSION GROUP (Experimenters, CNES)
CESR (IDP)
ESTEC (ISL)
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One day in the DEMETER life (August 12, 2004)
d 2800 km 10 LT 22 LT
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Outlines The Project The hypotheses about
the seismo EM effect Observations during seismic
activities Statistical analysis Conclusions
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• Hypotheses on the generation mechanism of these
  seismo-electromagnetic perturbations
• Propagation of EM waves from the ground.
• Only ULF waves can appear at the Earths surface,
• Propagation in a wave guide (the fault) or change
  in the ground resistivity?
• Wave-wave interaction in the ionosphere.
• Propagation of Acoustic-Gravity Waves.
• As far as they propagate, the AGW amplitude
  increases due the decrease of the atmospheric
  density

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• The piezo-electric and tribo-electric effects.
• Apparition of electric charges at the Earths
  surface,
• Change of the atmospheric conductivity,
• Change of the atmosphere-ionosphere coupling
  currents
• The emissions of aerosols (radioactive gas or
  metallic ions). Transportation to ionospheric
  layers due to
• atmospheric turbulence and thermospheric winds,
• increase of the atmosphere conductivity,
  penetration of electric fields and ion
  acceleration

from Markson, 1978
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First paper on the seismo-electromagnetic effects
by Milne in 1890
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Gokhberg et al. (1982)
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Observations of Seismo-Electromagnetic effects

• Laboratory experiment (Cress et al., GRL, 1987)

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Observations of Seismo-Electromagnetic effects

• Radon concentration data in a well close to Kobe

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(courtesy of P.F. Biagi)
Ground
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Outlines The Project The hypotheses about
the seismo EM effect Observations during seismic
activities Statistical analysis Conclusions
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Examples of ionospheric perturbations in possible
correlation with seismic activity
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Altitude of DEMETER
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13 Juin 2008 234346 UT Lat 39.103 Long
140.668 d 10 km M 6.8
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2,5 days before
200 km
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from K. Hattori
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Outlines The Project The hypotheses about
the seismo EM effect Observations during seismic
activities Statistical analysis Conclusions
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Statistical analysis with the electric field data
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• 15 months of data
• 4385 hours of measurements
• Electric field data organized by
• Frequencies (16) below 10 kHz
• Magnetic local time (2)
• Geographic positions (bin of 4 in longitude, 2
  in latitude)
• Kp classes (3)
• Seasons (2)

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Electric field map
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Application of the central limit therorem
Probability density of the intensity of the
waves in a cell
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de Braile, AGU, 2004
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Superposed epoch method
Time of EQ 26 June 2007 003000 UT
10 Hours before
?
x
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14 Hours 30 after
x
?
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Night time VLF Electric field between 1055 2383
Hz
2111 EQs with M gt 5.0 and d lt 40 km
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3346 earthquakes with M gt 4.8 and d lt 40 km
2111 earthquakes with M gt 5.0 and d lt 40 km
Night time
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random
2111 earthquakes with M gt 5.0 and d lt 40 km
Night time
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We observe a decrease of the electric field at
1.7 kHz during night time This is the frequency
cutoff of the Earth-ionosphere waveguide (h 90
km)
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Conclusions (1/3)

• The main points revealed by the statistical
  studies are
• The values of the parameters when the satellite
  is far from the earthquakes are similar to the
  values obtained when a random data set of events
  is used. Therefore this study shows that there is
  an influence of the seismic activity on the
  ionospheric parameters at an altitude of 700 km
  before the earthquakes.
• The perturbations are observed a few hours before
  the earthquakes.
• The perturbations are real but they are weak and
  only statistically revealed. Up to now nothing
  can be said about the possibility to predict
  earthquakes with the analysis of the ionospheric
  parameters.

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Conclusions (2/3)

• Statistical analysis are in progress with other
  parameters
• Electron density
• Electrostatic turbulence
• Whistler dispersion
• Energetic particles
• VLF Transmitters

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Conclusions (3/3)

• 72 publications (end of May)
• The website of the mission http//demeter.cnrs-or
  leans.fr
• Operations will continue at least until the
  beginning of 2010.