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| Titel |
The Level 2 research product algorithms for the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) |
| VerfasserIn |
P. Baron, J. Urban, H. Sagawa, J. Möller, D. P. Murtagh, J. Mendrok, E. Dupuy, T. O. Sato, S. Ochiai, K. Suzuki, T. Manabe, T. Nishibori, K. Kikuchi, R. Sato, M. Takayanagi, Y. Murayama, M. Shiotani, Y. Kasai |
| 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 ; 4, no. 10 ; Nr. 4, no. 10 (2011-10-11), S.2105-2124 |
| Datensatznummer |
250002112
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| Publikation (Nr.) |
 copernicus.org/amt-4-2105-2011.pdf |
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| Zusammenfassung |
| This paper describes the algorithms of the level-2 research (L2r) processing
chain developed for the Superconducting Submillimeter-Wave Limb-Emission
Sounder (SMILES). The chain has been developed in parallel to the operational
chain for conducting researches on calibration and retrieval algorithms. L2r
chain products are available to the scientific community. The objective of
version 2 is the retrieval of the vertical distribution of trace gases in the
altitude range of 18–90 km. A theoretical error analysis is conducted to
estimate the retrieval feasibility of key parameters of the processing:
line-of-sight elevation tangent altitudes (or angles), temperature and
ozone profiles.
While pointing information is often retrieved from molecular oxygen lines,
there is no oxygen line in the SMILES spectra, so the strong ozone line at 625.371 GHz has been chosen.
The pointing parameters and the ozone profiles are retrieved from the line wings which are measured with
high signal to noise ratio, whereas the temperature profile is retrieved from the optically thick line center.
The main systematic component of the retrieval error was found to be the neglect
of the non-linearity of the radiometric gain in the calibration procedure.
This causes a temperature retrieval error of 5–10 K. Because of these large temperature
errors, it is not possible to construct a reliable hydrostatic pressure profile.
However, as a consequence of the retrieval of pointing parameters, pressure induced errors are
significantly reduced if the retrieved trace gas profiles are represented on pressure levels instead of geometric altitude levels.
Further, various setups of trace gas retrievals have been tested.
The error analysis for the retrieved HOCl profile
demonstrates that best results for inverting weak lines can be obtained by
using narrow spectral windows. |
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