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| Titel |
Zernike polynomials applied to apparent solar disk flattening for pressure profile retrievals |
| VerfasserIn |
E. Dekemper, F. Vanhellemont, N. Mateshvili, G. Franssens, D. Pieroux, C. Bingen, C. Robert, D. Fussen |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1867-1381
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| Digitales Dokument |
URL |
| Erschienen |
In: Atmospheric Measurement Techniques ; 6, no. 3 ; Nr. 6, no. 3 (2013-03-27), S.823-835 |
| Datensatznummer |
250017851
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| Publikation (Nr.) |
 copernicus.org/amt-6-823-2013.pdf |
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| Zusammenfassung |
We present a passive method for the retrieval of atmospheric pressure
profiles based on the measurement of the apparent flattening of the solar
disk as observed through the atmosphere by a spaceborne imager.
This method was applied to simulated sunsets. It relies on accurate
representation of the solar disk, including its limb darkening, and how its
image is affected by atmospheric refraction. The Zernike polynomials are used
to quantify the flattening in the Sun images.
The inversion algorithm relies on a transfer matrix providing the link
between the atmospheric pressure profile and a sequence of Zernike moments
computed on the sunset frames. The transfer matrix is determined by a
training dataset of pressure profiles generated from a standard climatology.
The performance and limitations of the method are assessed by two test cases.
Pressure profiles similar to the training dataset show that retrieval error
can be up to 10 times smaller than the natural variability in the lower
mesosphere, and up to 500 times smaller in the upper troposphere. Tests with other
independent profiles emphasize the need for better representativeness of the
training dataset. |
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