The Detection of Sferics by a Nano-Satellite
- Paper number
IAC-08.B4.2.12
- Author
Prof. Otto Koudelka, Graz University of Technology, Austria
- Coauthor
Mr. Gulam Jaffer, Graz University of Technology, Austria
- Coauthor
Dr. Konrad Schwingenschuh, Austrian Academy of Sciences, Austria
- Coauthor
Mr. Hans-Ulrich Eichelberger, Austrian Academy of Sciences, Austria
- Year
2008
- Abstract
The paper describes a project for a nanosatellite mission for lightnig detection from Space. The main scientific objective of the planned TUGSat-Lightning nano-satellite is the investigation of impulsive electromagnetic signals generated by electrical discharges in terrestrial thunderstorms (lightning), blizzards, volcanic eruptions, earthquakes and dust devils. These electromagnetic phenomena, called Sferics cover the frequency range from a few Hertz (Schumann Resonances) up to several Gigahertz. Depending on the source mechanism, the wave power is peaking at different frequencies, e.g. terrestrial lightning has a maximum power in the VLF range. The global terrestrial lightning rate is in the order of 100 lightning flashes per second with an average energy per flash of about 10E9 Joule. Only a small percentage of the total energy is converted to electromagnetic radiation. The signal received by a satellite radio experiment depends on the distance and the energy of a lightning stroke as well as on the orientation of the discharge channel. The nano-satellite project under study emphasizes on the investigation of the global distribution and temporal variation of lightning phenomena using electromagnetic signals. In contrast to optical satellite observations the sferics produced by lightning can be observed on the day and night side but with a smaller spatial resolution. We know from the FORTE satellite mission that in an altitude of about 1000 km the impulsive events produced by lightning can reach amplitudes up to 1 mV/m in a 1 MHz band around 40 MHz. The small spacecraft is based on the design and bus similar to the TUGSAT-1 / BRITE-AUSTRIA astronomical satellite which is currently in Phase C/D. It will carry a radio-frequency receiver payload for the investigation of electromagnetic signatures produced by lightning strokes. Special emphasis will be on the investigation of transient electromagnetic waves in the frequency range of 20-40MHz, known as sferics. The onboard RF lightning triggering system will be a special capability of the nano-satellite. The lightning experiment will also observe signals of ionospheric and magnetospheric origin. Adaptive filters have been developed to differentiate terrestrial electromagnetic impulsive signals from ionospheric or magnetospheric signals. One of the major problems using a nano-satellite is to integrate the lightning experiment antenna, receiver and data acquisition unit into the nano-satellite structure. Using a gravity gradient boom as a lightning antenna will increase the sensitivity and directional capability. The TUGSat-Lightning team has participated in various space missions investigating electromagnetic phenomena. The data of these missions will be used to test the hard- and software of the lightning experiment before integration inot the spacecraft. The paper describes the lightning detection payload and antenna, the nanosatellite, the interfacing with the housekeeping and telemetry computer as well as modes of operation. EMC issues are specially treated. Results of tests of the payload in a simulated environment are presented. The material of this paper has not been published before. It is assured that the authors will be present at IAC2008 to personally present the paper. Funding for participation is guaranteed by Graz University of Technology.
- Abstract document
- Manuscript document
IAC-08.B4.2.12.pdf (🔒 authorized access only).
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