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The DEMETER satellite: Payload, Operations and Data

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  1. The DEMETERsatellite: Payload, Operations and Data M. Parrot LPC2E/CNRS 3A, Avenue de la Recherche 45071 Orléans cedex 2, France E-mail: mparrot@cnrs-orleans.fr Tunis, Awesome June 2009

  2. Outlines The Project The hypotheses about the seismo EM effect Observations during seismic activities Statistical analysis Conclusions Tunis, Awesome June 2009

  3. 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. Tunis, Awesome June 2009

  4. 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. Tunis, Awesome June 2009

  5. 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). Tunis, Awesome June 2009

  6. Tunis, Awesome June 2009

  7. Tunis, Awesome June 2009

  8. Tunis, Awesome June 2009

  9. 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 Tunis, Awesome June 2009

  10. 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. Tunis, Awesome June 2009

  11. Tunis, Awesome June 2009

  12. 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. Tunis, Awesome June 2009

  13. Tunis, Awesome June 2009

  14. The DEMETER mission center 8 GHz 2 GHz EXCHANGE FILE SERVICE ANCILLARY DATA PROCESSING PRE-PROCESSING [L0] (Decommutation, Good Health) INSTRUMMENT CALIBRATIONS PHYSICAL VALUES PROCESSING [L1] ARCHIVE (Science data L0, QL, L1; Earthquake data; Ancillary data) High resolution display [L2] WEB DATA SERVER (Data L0, QL, L1, L2; Earthquake events; Ancillary data products; Mission information) CNES ANCILLARY DATA - Orbit Parameters - TM station Pass-Planning - Events (orbit, satellite) - Attitude - HK CONTROL CENTER OPERATION COORDINATION GROUP Science PL TM packets « back-up » Science PL TM packets 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) Tunis, Awesome June 2009

  15. Tunis, Awesome June 2009

  16. Tunis, Awesome June 2009

  17. Tunis, Awesome June 2009

  18. One day in the DEMETER life (August 12, 2004) d = 2800 km 10 LT 22 LT Tunis, Awesome June 2009

  19. Outlines The Project The hypotheses about the seismo EM effect Observations during seismic activities Statistical analysis Conclusions Tunis, Awesome June 2009

  20. 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 Tunis, Awesome June 2009

  21. 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 Tunis, Awesome June 2009

  22. First paper on the seismo-electromagnetic effects by Milne in 1890 Tunis, Awesome June 2009

  23. Gokhberg et al. (1982) Tunis, Awesome June 2009

  24. Observations of Seismo-Electromagnetic effects Laboratory experiment (Cress et al., GRL, 1987) Tunis, Awesome June 2009

  25. Observations of Seismo-Electromagnetic effects Radon concentration data in a well close to Kobe Tunis, Awesome June 2009

  26. (courtesy of P.F. Biagi) Tunis, Awesome June 2009 Ground

  27. Outlines The Project The hypotheses about the seismo EM effect Observations during seismic activities Statistical analysis Conclusions Tunis, Awesome June 2009

  28. Examples of ionospheric perturbations in possible correlation with seismic activity Tunis, Awesome June 2009

  29. Altitude of DEMETER Tunis, Awesome June 2009

  30. 13 Juin 2008 23:43:46 UT Lat 39.103° Long 140.668° d = 10 km M = 6.8 Tunis, Awesome June 2009

  31. 2,5 days before 200 km Tunis, Awesome June 2009

  32. from K. Hattori Tunis, Awesome June 2009

  33. Outlines The Project The hypotheses about the seismo EM effect Observations during seismic activities Statistical analysis Conclusions Tunis, Awesome June 2009

  34. Statistical analysis with the electric field data Tunis, Awesome June 2009

  35. 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) Tunis, Awesome June 2009

  36. Electric field map Tunis, Awesome June 2009

  37. Probability density of the intensity of the waves in a cell Application of the central limit therorem Tunis, Awesome June 2009

  38. de Braile, AGU, 2004 Tunis, Awesome June 2009

  39. Superposed epoch method Time of EQ 26 June 2007 00:30:00 UT 10 Hours before ► x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x 14 Hours 30 after x ► Tunis, Awesome June 2009

  40. Night time VLF Electric field between 1055 – 2383 Hz 2111 EQs with M > 5.0 and d < 40 km Tunis, Awesome June 2009

  41. 3346 earthquakes with M > 4.8 and d < 40 km 2111 earthquakes with M > 5.0 and d < 40 km Night time Tunis, Awesome June 2009

  42. random 2111 earthquakes with M > 5.0 and d < 40 km Night time Tunis, Awesome June 2009

  43. 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) Tunis, Awesome June 2009

  44. 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. Tunis, Awesome June 2009

  45. Conclusions (2/3) • Statistical analysis are in progress with other parameters: • Electron density • Electrostatic turbulence • Whistler dispersion • Energetic particles • VLF Transmitters Tunis, Awesome June 2009

  46. 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. Tunis, Awesome June 2009