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| Titel |
Determination of meteoroid physical properties from tristatic radar observations |
| VerfasserIn |
J. Kero, C. Szasz, A. Pellinen-Wannberg, G. Wannberg, A. Westman, D. D. Meisel |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 26, no. 8 ; Nr. 26, no. 8 (2008-08-05), S.2217-2228 |
| Datensatznummer |
250016180
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| Publikation (Nr.) |
 copernicus.org/angeo-26-2217-2008.pdf |
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| Zusammenfassung |
| In this work we give a review of the meteor head echo observations carried
out with the tristatic 930 MHz EISCAT UHF radar system during four 24 h runs
between 2002 and 2005 and compare these with earlier observations. A total
number of 410 tristatic meteors were observed. We describe a method to
determine the position of a compact radar target in the common volume
monitored by the three receivers and demonstrate its applicability for meteor
studies. The inferred positions of the meteor targets have been utilized to
estimate their velocities, decelerations and directions of arrival as well as
their radar cross sections with unprecedented accuracy. The velocity
distribution of the meteoroids is bimodal with peaks at 35–40 km/s and
55–60 km/s, and ranges from 19–70 km/s. The estimated masses are between
10−9–10−5.5 kg. There are very few detections below 30 km/s. The
observations are clearly biased to high-velocity meteoroids, but not so
biased against slow meteoroids as has been presumed from previous tristatic
measurements. Finally, we discuss how the radial deceleration observed with a
monostatic radar depends on the meteoroid velocity and the angle between the
trajectory and the beam. The finite beamwidth leads to underestimated
meteoroid masses if radial velocity and deceleration of meteoroids
approaching the radar are used as estimates of the true quantities in a
momentum equation of motion. |
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