Tunis, Awesome June 2009 The DEMETER satellite: Payload, Operations and Data M. Parrot LPC2E/CNRS 3A, Avenue de la Recherche 45071 Orléans cedex 2, France

Tunis, Awesome June 2009

The DEMETER satellite: Payload, Operations and Data

M. Parrot

LPC2E/CNRS

3A, Avenue de la Recherche

45071 Orléans cedex 2,

France

E-mail: [email protected]


Outlines

The Project

The hypotheses about the seismo EM effect

Observations during seismic activities

Statistical analysis

Conclusions


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.


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.


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).





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


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.


d1d3

d2 d4

Earthquakeepicenter

Conjugate point of the epicenter

South conjugate pointof the epicenter at the satellite altitude

North conjugate point of the epicenter at the satellite altitude

DEMETER orbit

dm

dmcN

dmc

dmcS South conjugate pointof the epicenter at the satellite altitude


DEMETER orbit


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.



LPCE(IMSC, RNF, BANT)

DEMETER DATA ACQUISITION

ARCHIVE(Science data L0, QL, L1; Earthquake data;

Ancillary data)

WEB DATA SERVER(Data L0, QL, L1, L2; Earthquake events; Ancillary data products;

Mission information)

Science PL TM packetsPL TC

PLAN

SCIENCE PL PROGRAMMATION

GENERATION

CONTROL CENTER

PHYSICAL VALUES PROCESSING [L1]

ANCILLARY DATA - Orbit Parameters - TM station Pass-Planning

- Events (orbit, satellite) - Attitude - HK

OPERATIONBOARDOPERATION

BOARD

DEMETERMISSION GROUP

(Experimenters,CNES)

DEMETERMISSION GROUP

(Experimenters,CNES)

Scienceoperationcoordination

PL and MCevents

Memoryhandling

BURST zones

LPCE(MC)

CETP(IAP, ICE)

8 GHz

SCIENTIFICUSERS

SCIENTIFICUSERS

Science PLTM packets « back-up »

QUICK-LOOKPROCESSING [L0']

PRE-PROCESSING [L0](Decommutation, Good Health)

TM

CESR(IDP) ESTEC

(ISL)

IPGPSEISMIC DATA

Calibrationvalidation

Instrumentconfiguration

2 GHz

CNES

EXCHANGE FILE SERVICE

ANCILLARY DATAPROCESSING

INSTRUMMENT CALIBRATIONS

High resolutiondisplay [L2]

PL status

OPERATIONCOORDINATION

GROUP

OPERATIONCOORDINATION

GROUP

The DEMETER mission center





One day in the DEMETER life (August 12, 2004)

d = 2800 km10 LT22 LT


Outlines

The Project




Conclusions


Hypotheses on the generation mechanism of these seismo-

electromagnetic perturbations:

•Propagation of EM waves from the ground.–Only ULF waves can appear at the Earth’s 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


•The piezo-electric and tribo-electric effects.–Apparition of electric charges at the Earth’s 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


First paper on the seismo-electromagnetic effects by Milne in 1890


Gokhberg et al. (1982)


Observations of Seismo-Electromagnetic effects

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


Observations of Seismo-Electromagnetic effects

Radon concentration data in a well close to Kobe


(courtesy of P.F. Biagi)


Outlines

The Project




Conclusions


Examples of ionospheric perturbations in possible correlationwith seismic activity


Altitude ofDEMETER


13 Juin 200823:43:46 UTLat 39.103°

Long 140.668°d = 10 kmM = 6.8


d1d3

d2 d4

Earthquakeepicenter

Conjugate point of the epicenter

South conjugate pointof the epicenter at the satellite altitude


DEMETER orbit

2,5 days before

200 km

Tunis, Awesome June 2009from K. Hattori


Outlines

The Project




Conclusions


Statistical analysis with the electric field data


15 months of data4385 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)


Electric field map


Application of the central limit therorem

Probability density of the intensity of the waves in a cell


de Braile, AGU, 2004


Time of EQ26 June 200700:30:00 UT

10 Hours before

14 Hours 30 after

►

►

xx

xxxxxxxx

x

x

x

x

x

xx

xx

xx

x

xx

x

x

x

x

xx

x

x

Superposed epoch method


2111 EQs with M > 5.0 and d < 40 km

Night time VLF Electric field between 1055 – 2383 Hz


3346 earthquakes with M > 4.8 and d < 40 km

2111 earthquakes with M > 5.0 and d < 40 km

Night time


random 2111 earthquakes with M > 5.0 and d < 40 km

Night time


We observe a decrease of the electric field at ~ 1.7 kHzduring night time

This is the frequency cutoff of the Earth-ionospherewaveguide (h= 90 km)


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.


Conclusions (2/3)

Statistical analysis are in progress with other parameters:

- Electron density- Electrostatic turbulence- Whistler dispersion- Energetic particles- VLF Transmitters


Conclusions (3/3)

72 publications (end of May)

The website of the mission: http://demeter.cnrs-orleans.fr

Operations will continue at least until the beginning of 2010.

http://demeter.cnrs-orleans.fr/

http://demeter.cnrs-orleans.fr/

Documents

Tunis, Awesome June 2009 The DEMETER satellite: Payload, Operations and Data M. Parrot LPC2E/CNRS 3A, Avenue de la Recherche 45071 Orléans cedex 2, France