Linearisation of the effects of spectral shift and stretch in DOAS analysis
Differential Optical Absorption Spectroscopy (DOAS) is a widely used method to quantify atmospheric trace gases from spectroscopic measurements. While DOAS can, in principal, be described by a linear equation system, usually nonlinearities occur, in particular as a consequence of spectral misalignme...
| 發表在: | Atmospheric Measurement Techniques |
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| Main Authors: | , , |
| 格式: | Article |
| 語言: | 英语 |
| 出版: |
Copernicus Publications
2013-03-01
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| 在線閱讀: | http://www.atmos-meas-tech.net/6/661/2013/amt-6-661-2013.pdf |
| 總結: | Differential Optical Absorption Spectroscopy (DOAS) is a widely used method to quantify atmospheric trace gases from spectroscopic measurements. While DOAS can, in principal, be described by a linear equation system, usually nonlinearities occur, in particular as a consequence of spectral misalignments. <br><br> Here we propose to linearise the effects of a spectral shift by including a "shift spectrum", which is the first term of a Taylor expansion, as pseudo-absorber in the DOAS fit. The effects of a spectral stretch are considered as additional wavelength-dependent shifts. <br><br> Solving the DOAS equation system linearly has several advantages: the solution is unique, the algorithm is robust, and it is very fast. The latter might be particularly important for measurements with high data rates, like for upcoming satellite missions. |
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| ISSN: | 1867-1381 1867-8548 |