[EPFL] [University of Kentucky]
[The International Meteor Organization]
For additional materials and news coverage of the GEFS project go to the NEWS pages

November 2002: The first review of almost 100 witness reportes collected by GEFS:
Vinkovic, D., Garaj, S., Lim, P. L., Kovacic, D., Zgrablic, G., Andreic, Z. " Global Electrophonic Fireball Survey: a review of witness reports - I. ", WGN, the Journal of the IMO, Vol.30, December 2002, pp.244-257
ABSTRACT: " Despite more than 300 years since its first scientific description, the phenomenon of electrophonic sounds from meteors is still eluding complete physical explanation. According to the accepted knowledge, the sound itself is created by strong electric fields on the ground induced by the meteor. Nonetheless, there is no convincing theory that can fully explain how a meteor can generate such a strong electric field. Extreme rareness of the phenomenon has prevented a substantial experimental work so far; thus, consequently, it remains on the margins of scientific interest. This is quite unfortunate since these electric fields suggest existence of a highly complex electromagnetic coupling and charge dynamics between the meteors and the ionosphere. Therefore, the existing theoretical work relies mostly on the witness reports. The Global Electrophonic Fireball Survey (GEFS) is the first systematic survey of witness reports of these sounds with a standardized questionnaire designed exclusively for this phenomenon. Here we present the overall picture of the phenomenon that emerged after almost 100 reports collected by GEFS. It becomes clear now that the lover meteor brightness limit is about -2m, suggesting a bias in the existing electrophonic sounds catalogues toward brighter meteors. In contrast to the current belief that such low brightness electrophonic meteors produce transient sounds, we find that they can also produce sustained sounds. The current theories can not accommodate these results. We revive the old idea that the electrophonic sounds can be created by the corona discharge mechanism, in addition to the existing prevalent suggestion of resonant vibration of objects on the ground. "
download: WGN_GEFS_review1.pdf    WGN_GEFS_review1.ps.gz
(or at arXiv.org: arxiv.org/abs/astro-ph/0211203)

The first instrumental recording of electrophonic sounds recorded during the 1998 Leonids in Mongolia. The analysis yielded interesting results and showed that the current theories cannot explain them.
Zgrablic, G., Vinkovic, D., Gradecak, S., Kovacic, D., Biliskov, N., Grbac, N., Andreic, Z., Garaj, S., "Instrumental recording of electrophonic sounds from Leonid fireballs" Journal of Geophysical Research - Space Phys. 107(A7), 10.1029/2001JA000310 (2002)
      - read more about it: here

The GEFS Submission Form published in WGN
Vinkovic, D., Andreic, Z., Garaj, S., Kovacic, D., Mladinov, M., Zgrablic, G., "Global Electrophonic Fireball Survey" WGN, the journal of the IMO, 28, 48-53 (2000)
      - download:  gziped PostScript    or   PDF