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| Titel |
A meteor head echo analysis algorithm for the lower VHF band |
| VerfasserIn |
J. Kero, C. Szasz, T. Nakamura, T. Terasawa, H. Miyamoto, K. Nishimura |
| 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 ; 30, no. 4 ; Nr. 30, no. 4 (2012-04-02), S.639-659 |
| Datensatznummer |
250017208
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| Publikation (Nr.) |
 copernicus.org/angeo-30-639-2012.pdf |
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| Zusammenfassung |
| We have developed an automated analysis scheme for meteor head echo
observations by the 46.5 MHz Middle and Upper atmosphere (MU) radar near
Shigaraki, Japan (34.85° N, 136.10° E). The analysis
procedure computes meteoroid range, velocity and deceleration as functions of
time with unprecedented accuracy and precision. This is crucial for
estimations of meteoroid mass and orbital parameters as well as
investigations of the meteoroid-atmosphere interaction processes. In this
paper we present this analysis procedure in detail. The algorithms use a
combination of single-pulse-Doppler, time-of-flight and pulse-to-pulse phase
correlation measurements to determine the radial velocity to within a few
tens of metres per second with 3.12 ms time resolution. Equivalently, the
precision improvement is at least a factor of 20 compared to previous
single-pulse measurements. Such a precision reveals that the deceleration
increases significantly during the intense part of a meteoroid's ablation
process in the atmosphere. From each received pulse, the target range is
determined to within a few tens of meters, or the order of a few hundredths
of the 900 m long range gates. This is achieved by transmitting a 13-bit
Barker code oversampled by a factor of two at reception and using a novel
range interpolation technique. The meteoroid velocity vector is determined
from the estimated radial velocity by carefully taking the location of the
meteor target and the angle from its trajectory to the radar beam into
account. The latter is determined from target range and bore axis offset. We
have identified and solved the signal processing issue giving rise to the
peculiar signature in signal to noise ratio plots reported by
Galindo et al. (2011), and show how
to use the range interpolation technique to differentiate the effect of
signal processing from physical processes. |
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