Characterization and correction of stray light in TROPOMI-SWIR
<p>The shortwave infrared (SWIR) spectrometer module of the Tropospheric Monitoring Instrument (TROPOMI), on board the ESA Copernicus Sentinel-5 Precursor satellite, is used to measure atmospheric CO and methane columns. For this purpose, calibrated radiance measurements are needed that are...
| Main Authors: | , , , , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2018-07-01
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| Series: | Atmospheric Measurement Techniques |
| Online Access: | https://www.atmos-meas-tech.net/11/4493/2018/amt-11-4493-2018.pdf |
| _version_ | 1811231653143511040 |
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| author | P. J. J. Tol T. A. van Kempen R. M. van Hees M. Krijger M. Krijger S. Cadot S. Cadot R. Snel R. Snel S. T. Persijn I. Aben R. W. M. Hoogeveen |
| author_facet | P. J. J. Tol T. A. van Kempen R. M. van Hees M. Krijger M. Krijger S. Cadot S. Cadot R. Snel R. Snel S. T. Persijn I. Aben R. W. M. Hoogeveen |
| author_sort | P. J. J. Tol |
| collection | DOAJ |
| description | <p>The shortwave infrared (SWIR) spectrometer module of the Tropospheric
Monitoring Instrument (TROPOMI), on board the ESA Copernicus Sentinel-5
Precursor satellite, is used to measure atmospheric CO and methane columns.
For this purpose, calibrated radiance measurements are needed that are
minimally contaminated by instrumental stray light. Therefore, a method has
been developed and applied in an on-ground calibration campaign to
characterize stray light in detail using a monochromatic quasi-point light
source. The dynamic range of the signal was extended to more than 7 orders of magnitude by performing measurements with different exposure times,
saturating detector pixels at the longer exposure times. Analysis of the
stray light indicates about 4.4 % of the detected light is correctable stray
light. An algorithm was then devised and implemented in the operational data
processor to correct in-flight SWIR observations in near-real time, based on
Van Cittert deconvolution. The stray light is approximated by a far-field
kernel independent of position and wavelength and an additional kernel
representing the main reflection. Applying this correction significantly
reduces the stray-light signal, for example in a simulated dark forest scene
close to bright clouds by a factor of about 10. Simulations indicate that
this reduces the stray-light error sufficiently for accurate gas-column
retrievals. In addition, the instrument contains five SWIR diode lasers that
enable long-term, in-flight monitoring of the stray-light distribution.</p> |
| first_indexed | 2024-04-12T10:49:41Z |
| format | Article |
| id | doaj.art-196d907f472648868d70c75a3a844e72 |
| institution | Directory Open Access Journal |
| issn | 1867-1381 1867-8548 |
| language | English |
| last_indexed | 2024-04-12T10:49:41Z |
| publishDate | 2018-07-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Measurement Techniques |
| spelling | doaj.art-196d907f472648868d70c75a3a844e722022-12-22T03:36:17ZengCopernicus PublicationsAtmospheric Measurement Techniques1867-13811867-85482018-07-01114493450710.5194/amt-11-4493-2018Characterization and correction of stray light in TROPOMI-SWIRP. J. J. Tol0T. A. van Kempen1R. M. van Hees2M. Krijger3M. Krijger4S. Cadot5S. Cadot6R. Snel7R. Snel8S. T. Persijn9I. Aben10R. W. M. Hoogeveen11SRON Netherlands Institute for Space Research, Utrecht, the NetherlandsSRON Netherlands Institute for Space Research, Utrecht, the NetherlandsSRON Netherlands Institute for Space Research, Utrecht, the NetherlandsSRON Netherlands Institute for Space Research, Utrecht, the NetherlandsEarth Space Solutions, Utrecht, the NetherlandsSRON Netherlands Institute for Space Research, Utrecht, the NetherlandsJigsaw B.V., Delft, the NetherlandsSRON Netherlands Institute for Space Research, Utrecht, the NetherlandsScience and Technology B.V., Delft, the NetherlandsVSL Dutch Metrology Institute, Delft, the NetherlandsSRON Netherlands Institute for Space Research, Utrecht, the NetherlandsSRON Netherlands Institute for Space Research, Utrecht, the Netherlands<p>The shortwave infrared (SWIR) spectrometer module of the Tropospheric Monitoring Instrument (TROPOMI), on board the ESA Copernicus Sentinel-5 Precursor satellite, is used to measure atmospheric CO and methane columns. For this purpose, calibrated radiance measurements are needed that are minimally contaminated by instrumental stray light. Therefore, a method has been developed and applied in an on-ground calibration campaign to characterize stray light in detail using a monochromatic quasi-point light source. The dynamic range of the signal was extended to more than 7 orders of magnitude by performing measurements with different exposure times, saturating detector pixels at the longer exposure times. Analysis of the stray light indicates about 4.4 % of the detected light is correctable stray light. An algorithm was then devised and implemented in the operational data processor to correct in-flight SWIR observations in near-real time, based on Van Cittert deconvolution. The stray light is approximated by a far-field kernel independent of position and wavelength and an additional kernel representing the main reflection. Applying this correction significantly reduces the stray-light signal, for example in a simulated dark forest scene close to bright clouds by a factor of about 10. Simulations indicate that this reduces the stray-light error sufficiently for accurate gas-column retrievals. In addition, the instrument contains five SWIR diode lasers that enable long-term, in-flight monitoring of the stray-light distribution.</p>https://www.atmos-meas-tech.net/11/4493/2018/amt-11-4493-2018.pdf |
| spellingShingle | P. J. J. Tol T. A. van Kempen R. M. van Hees M. Krijger M. Krijger S. Cadot S. Cadot R. Snel R. Snel S. T. Persijn I. Aben R. W. M. Hoogeveen Characterization and correction of stray light in TROPOMI-SWIR Atmospheric Measurement Techniques |
| title | Characterization and correction of stray light in TROPOMI-SWIR |
| title_full | Characterization and correction of stray light in TROPOMI-SWIR |
| title_fullStr | Characterization and correction of stray light in TROPOMI-SWIR |
| title_full_unstemmed | Characterization and correction of stray light in TROPOMI-SWIR |
| title_short | Characterization and correction of stray light in TROPOMI-SWIR |
| title_sort | characterization and correction of stray light in tropomi swir |
| url | https://www.atmos-meas-tech.net/11/4493/2018/amt-11-4493-2018.pdf |
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