A tool to maximize the scientific output of PWI target physics: Intelligent Signal Detector Module

1. A tool to maximize the scientific output of PWI target physics: Intelligent Signal Detector Module J. Lichtenberger (1), P. Steinbach (2) and L. Bodnár (3) Space Research Group, Department of Geophysics, Eötvös University, Budapest, Hungary MTA-ELTE Research Group for Geoinformatics and Space Sciences BL Electronics, Solymár, Hungary

2. Science vs. Technology? Science in a space experiments is limited by technology → cannot speak about science without taking technology into account Hard limits: sensors/preamps/sensor location, etc. Soft(er) limits: data collection/processing policy, mode of operation

3. Science vs. Technology? Example 1: measurement averaged over 4 sec spin of MMO (a planned mode) → most of the phenomena (physics) shorter than this period is lost Example 2: achieving ~1Hz@60kHz resolution at ULF band in PWI, a very long (32768 point) FFT window has to be used, this window is >500msec → the physics inside is lost

4. Short lived phenomena in Hermean magnetosphere • Lion roars: narrow-banded whistler-mode wave packets at the bottom of magnetic trough of magnetosheath mirror waves. (Smith and Tsurutani,1976; Zhang et al. 1998 on Geotail). f~0.1 fce. May be in Hermean magnetosphere (Baumjohann et. al, 2006)

5. Short lived phenomena in Hermean magnetosphere 2. Seismo-electromagnetic phenomena (intensive research in Earth): short e.m. emissions (impulses) propagating in magnetoionic medium →dispersion Is Mercury active in seismological sense?

6. Short lived phenomena in Hermean magnetosphere • Triggered emissions: wave-particle interaction in Hermean magnetosphere with radiation belt particles Has Mercury radiation belt and ring current (Blomberg and Cumnock, 2004) ?

7. Technology to maximize the scientific output of PWI target physics:Intelligent Signal Detector Module 1. Scientific goal Detecting events in PWI VLF data that are shorter than spinning time (4 sec) of MMO and thus beyond the capabilities of general modes of operation. The target events are : a.transients generated by atmospheric/magnetospheric processes lithospheric processes Solar wind-atmosphere interactions

8. Technology to maximize the scientific output of PWI target physics:Intelligent Signal Detector Module b. whistler mode waves generated by transients (see a.) wave-particle interactions nonlinear processes Solar wind – magnetosphere interactions Estimated event durations: for a.: microseconds-few milliseconds for b.: ten milliseconds-second

9. Technology to maximize the scientific output of PWI target physics:Intelligent Signal Detector Module c. any new phenomena - limited in time - limited in frequency Theoretical background: UWB short impulse solution of Maxwell’s Equations with arbitrary excitation signal – modeling!

10. Technology to maximize the scientific output of PWI target physics:Intelligent Signal Detector Module Functional description a. Input data Raw waveform from EWO or spectrogram (dynamic spectra) of the selected component. b. Output data Survey mode: the number of a selected event type during the given period Burst mode: detected event waveform or spectrogram Noise background monitoring

11. Technology to maximize the scientific output of PWI target physics:Intelligent Signal Detector Module Functional description c. Algorithm 2D image correlation using the spectrogram or matched filtering on time domain depending on the signal and CPU load. d. Patterns The patterns are generated using theoretical models/assumptions and can be: - predefined stored in code memory segment - generated on the fly using different parameter sets and adaptive -procedures depending on the available processing power - uploaded from the Earth (second phase of operation when enough experience/knowledge have been gathered during the mission)

12. Technology to maximize the scientific output of PWI target physics:Intelligent Signal Detector Module Functional description c. Algorithm 2D image correlation using the spectrogram or matched filtering on time domain depending on the signal and CPU load. d. Patterns The patterns are generated using theoretical models/assumptions and can be: - predefined stored in code memory segment - generated on the fly using different parameter sets and adaptive -procedures depending on the available processing power - uploaded from the Earth (second phase of operation when enough experience/knowledge have been gathered during the mission)

13. Technology to maximize the scientific output of PWI target physics:Intelligent Signal Detector Module Heritage ISDM concept is based on various satellite experiment : - ACTIVE, - COMPASS-2 - SAS2 using ISDM concept flew here - DEMETER satellites projects in developing phase: ISS-OBSTANOVKA, VOLCANO series, Venus Entry Probe Mission) Automatic Whistler Detector and Analyzer system working on various sites all over the world (Hungary; SANAE, Halley, Rothera – Antarctica; South Africa, New Zealand)

14. Event detection SW diagram Evaluationof events Publishevent for other apps. Triggering ! Input DataStream Event dependentdata proc. Send data toTM process MDP op system

15. Technology caveat and solution High frequency resolution in ULF range ↔ optimal time resolution in VLF range. The domain of signal energy localization proportional to time-bandwidth product T x B Heisenberg-Gabor inequality: T x B ≥ 1 – a signal cannot have arbitrarily small resolution in time and in frequency Solution: a. Alternating long and short FFT window b. Open ULF data stream with hardware or software