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| Titel |
Detection of particle layers in backscatter profiles: application to Antarctic lidar measurements |
| VerfasserIn |
J. Gazeaux, S. Bekki, P. Naveau, P. Keckhut, J. Jumelet, J. Parades, C. David |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1680-7316
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Chemistry and Physics ; 12, no. 7 ; Nr. 12, no. 7 (2012-04-03), S.3205-3217 |
| Datensatznummer |
250011007
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| Publikation (Nr.) |
 copernicus.org/acp-12-3205-2012.pdf |
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| Zusammenfassung |
| A detection method is proposed and studied to infer the presence of hidden
signals in a statistical way. It is applied here to the detection of Polar
Stratospheric Cloud (PSC) layers in lidar backscatter profiles measured over
the Dumont D'Urville station (Antarctica). PSCs appear as layers with
enhanced variance in non stationary, heteroscedastic signal profiles, between
two unknown altitudes to be estimated. The method is based on a three step
algorithm. The first step is the stationarization of the signal, the second
performs the maximum likelihoods estimation of the signal (PSC altitude range
and variance inside and outside the PSC layer). The last step uses a
Fisher-Snédécor test to decide whether the detection of PSC layer is
statistically significant. Performances and robustness of the method are
tested on simulated data with given statistical properties. Bias and
detection limit are estimated. The method is then applied to lidar
backscatter profiles measured in 2008. No PSC are detected during seasons
when PSCs are not expected to form. As expected, PSC layers are detected
during the austral winter and early spring. The effect of time averaging of
the profiles is investigated. The best compromise for detection of PSC layers
in lidar backscatter profiles acquired at Dumont D'Urville is a time
averaging window of 1 h typically. |
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