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| Titel |
The EISCAT meteor code |
| VerfasserIn |
G. Wannberg, A. Westman, J. Kero, C. Szasz, A. Pellinen-Wannberg |
| 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.2303-2309 |
| Datensatznummer |
250016189
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| Publikation (Nr.) |
 copernicus.org/angeo-26-2303-2008.pdf |
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| Zusammenfassung |
The EISCAT UHF system has the unique capability to determine meteor vector
velocities from the head echo Doppler shifts measured at the three sites.
Since even meteors spending a very short time in the common volume produce
analysable events, the technique lends itself ideally to mapping the orbits
of meteors arriving from arbitrary directions over most of the upper
hemisphere.
A radar mode optimised for this application was developed in 2001/2002. A
specially selected low-sidelobe 32-bit pseudo-random binary sequence is used
to binary phase shift key (BPSK) the transmitted carrier. The baud-length is
2.4 μs and the receiver bandwidth is 1.6 MHz to accommodate both the
resulting modulation bandwidth and the target Doppler shift. Sampling is at
0.6 μs, corresponding to 90-m range resolution. Target range and
Doppler velocity are extracted from the raw data in a multi-step
matched-filter procedure. For strong (SNR>5) events the Doppler velocity
standard deviation is 100–150 m/s. The effective range resolution is about
30 m, allowing very accurate time-of-flight velocity estimates. On average,
Doppler and time-of-flight (TOF) velocities agree to within about one part
in 103. Two or more targets simultaneously present in the beam can be
resolved down to a range separation <300 m as long as their Doppler
shifts differ by more than a few km/s. |
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