Spectral sizing of a coarse-spectral-resolution satellite sensor for XCO<sub>2</sub>
<p>Verifying anthropogenic carbon dioxide (<span class="inline-formula">CO<sub>2</sub></span>) emissions globally is essential to inform about the progress of institutional efforts to mitigate anthropogenic climate forcing. To monitor localized emission source...
| Main Authors: | , , , , , , , , , , , , , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2020-02-01
|
| Series: | Atmospheric Measurement Techniques |
| Online Access: | https://www.atmos-meas-tech.net/13/731/2020/amt-13-731-2020.pdf |
| _version_ | 1819039191420370944 |
|---|---|
| author | J. S. Wilzewski J. S. Wilzewski A. Roiger J. Strandgren J. Landgraf D. G. Feist D. G. Feist D. G. Feist V. A. Velazco N. M. Deutscher I. Morino H. Ohyama Y. Té R. Kivi T. Warneke J. Notholt M. Dubey R. Sussmann M. Rettinger F. Hase K. Shiomi A. Butz |
| author_facet | J. S. Wilzewski J. S. Wilzewski A. Roiger J. Strandgren J. Landgraf D. G. Feist D. G. Feist D. G. Feist V. A. Velazco N. M. Deutscher I. Morino H. Ohyama Y. Té R. Kivi T. Warneke J. Notholt M. Dubey R. Sussmann M. Rettinger F. Hase K. Shiomi A. Butz |
| author_sort | J. S. Wilzewski |
| collection | DOAJ |
| description | <p>Verifying anthropogenic carbon dioxide (<span class="inline-formula">CO<sub>2</sub></span>) emissions globally is essential to inform about the progress of institutional efforts to mitigate anthropogenic climate forcing. To monitor localized emission sources, spectroscopic satellite sensors have been proposed that operate on the <span class="inline-formula">CO<sub>2</sub></span> absorption bands in the shortwave-infrared (SWIR) spectral range with ground resolution as fine as a few tens of meters to about a hundred meters. When designing such sensors, fine ground resolution requires a trade-off towards coarse spectral resolution in order to achieve sufficient noise performance. Since fine ground resolution also implies limited ground coverage, such sensors are envisioned to fly in fleets of satellites, requiring low-cost and simple design, e.g., by restricting the spectrometer to a single spectral band.</p>
<p>Here, we use measurements of the Greenhouse Gases Observing Satellite (GOSAT) to evaluate the spectral resolution and spectral band selection of a prospective satellite sensor with fine ground resolution. To this end, we degrade GOSAT SWIR spectra of the <span class="inline-formula">CO<sub>2</sub></span> bands at 1.6 (SWIR-1) and 2.0 <span class="inline-formula">µ</span>m (SWIR-2) to coarse spectral resolution, without a further addition of noise, and we evaluate single-band retrievals of the column-averaged dry-air mole fractions of <span class="inline-formula">CO<sub>2</sub></span> (<span class="inline-formula">XCO<sub>2</sub></span>) by comparison to ground truth provided by the Total Carbon Column Observing Network (TCCON) and by comparison to global “native” GOSAT retrievals with native spectral resolution and spectral band selection. Coarsening spectral resolution from GOSAT's native resolving power of <span class="inline-formula">>20 000</span> to the range of 700 to a few thousand makes the scatter of differences between the SWIR-1 and SWIR-2 retrievals and<span id="page732"/> TCCON increase moderately. For resolving powers of 1200 (SWIR-1) and 1600 (SWIR-2), the scatter increases from 2.4 (native) to 3.0 ppm for SWIR-1 and 3.3 ppm for SWIR-2. Coarser spectral resolution yields only marginally worse performance than the native GOSAT configuration in terms of station-to-station variability and geophysical parameter correlations for the GOSAT–TCCON differences. Comparing the SWIR-1 and SWIR-2 configurations to native GOSAT retrievals on the global scale, however, reveals that the coarse-resolution SWIR-1 and SWIR-2 configurations suffer from some spurious correlations with geophysical parameters that characterize the light-scattering properties of the scene such as particle amount, size, height and surface albedo. Overall, the SWIR-1 and SWIR-2 configurations with resolving powers of 1200 and 1600 show promising performance for future sensor design in terms of random error sources while residual errors induced by light scattering along the light path need to be investigated further. Due to the stronger <span class="inline-formula">CO<sub>2</sub></span> absorption bands in SWIR-2 than in SWIR-1, the former has the advantage that measurement noise propagates less into the retrieved <span class="inline-formula">XCO<sub>2</sub></span> and that some retrieval information on particle scattering properties is accessible.</p> |
| first_indexed | 2024-12-21T08:49:17Z |
| format | Article |
| id | doaj.art-0d135186029d4514a4ce47b7c53d97ba |
| institution | Directory Open Access Journal |
| issn | 1867-1381 1867-8548 |
| language | English |
| last_indexed | 2024-12-21T08:49:17Z |
| publishDate | 2020-02-01 |
| publisher | Copernicus Publications |
| record_format | Article |
| series | Atmospheric Measurement Techniques |
| spelling | doaj.art-0d135186029d4514a4ce47b7c53d97ba2022-12-21T19:09:43ZengCopernicus PublicationsAtmospheric Measurement Techniques1867-13811867-85482020-02-011373174510.5194/amt-13-731-2020Spectral sizing of a coarse-spectral-resolution satellite sensor for XCO<sub>2</sub>J. S. Wilzewski0J. S. Wilzewski1A. Roiger2J. Strandgren3J. Landgraf4D. G. Feist5D. G. Feist6D. G. Feist7V. A. Velazco8N. M. Deutscher9I. Morino10H. Ohyama11Y. Té12R. Kivi13T. Warneke14J. Notholt15M. Dubey16R. Sussmann17M. Rettinger18F. Hase19K. Shiomi20A. Butz21Deutsches Zentrum für Luft- und Raumfahrt, Institut für Physik der Atmosphäre, Oberpfaffenhofen, GermanyMeteorological Institute Munich, Ludwig-Maximilians-Universität, Munich, GermanyDeutsches Zentrum für Luft- und Raumfahrt, Institut für Physik der Atmosphäre, Oberpfaffenhofen, GermanyDeutsches Zentrum für Luft- und Raumfahrt, Institut für Physik der Atmosphäre, Oberpfaffenhofen, GermanyNetherlands Institute for Space Research, Utrecht, the NetherlandsDeutsches Zentrum für Luft- und Raumfahrt, Institut für Physik der Atmosphäre, Oberpfaffenhofen, GermanyLudwig-Maximilians-Universität München, Lehrstuhl für Physik der Atmosphäre, Munich, GermanyMax Planck Institute for Biogeochemistry, Jena, GermanyCentre for Atmospheric Chemistry, School of Earth, Atmospheric and Life Sciences, University of Wollongong, NSW, AustraliaCentre for Atmospheric Chemistry, School of Earth, Atmospheric and Life Sciences, University of Wollongong, NSW, AustraliaNational Institute for Environmental Studies (NIES), Tsukuba, JapanNational Institute for Environmental Studies (NIES), Tsukuba, JapanLERMA-IPSL, Sorbonne Université, CNRS, Observatoire de Paris, Université PSL, 75005, Paris, FranceFinnish Meteorological Institute, FMI, Sodankylä, FinlandInstitute of Environmental Physics, University of Bremen, Bremen, GermanyInstitute of Environmental Physics, University of Bremen, Bremen, GermanyEarth System Observations, Los Alamos National Laboratory, Los Alamos, NM 87545, USAKarlsruhe Institute of Technology, IMK-IFU, Garmisch-Partenkirchen, GermanyKarlsruhe Institute of Technology, IMK-IFU, Garmisch-Partenkirchen, GermanyKarlsruhe Institute of Technology, IMK-ASF, Karlsruhe, GermanyJapan Aerospace Exploration Agency, Tsukuba, JapanInstitute of Environmental Physics, University of Heidelberg, Heidelberg, Germany<p>Verifying anthropogenic carbon dioxide (<span class="inline-formula">CO<sub>2</sub></span>) emissions globally is essential to inform about the progress of institutional efforts to mitigate anthropogenic climate forcing. To monitor localized emission sources, spectroscopic satellite sensors have been proposed that operate on the <span class="inline-formula">CO<sub>2</sub></span> absorption bands in the shortwave-infrared (SWIR) spectral range with ground resolution as fine as a few tens of meters to about a hundred meters. When designing such sensors, fine ground resolution requires a trade-off towards coarse spectral resolution in order to achieve sufficient noise performance. Since fine ground resolution also implies limited ground coverage, such sensors are envisioned to fly in fleets of satellites, requiring low-cost and simple design, e.g., by restricting the spectrometer to a single spectral band.</p> <p>Here, we use measurements of the Greenhouse Gases Observing Satellite (GOSAT) to evaluate the spectral resolution and spectral band selection of a prospective satellite sensor with fine ground resolution. To this end, we degrade GOSAT SWIR spectra of the <span class="inline-formula">CO<sub>2</sub></span> bands at 1.6 (SWIR-1) and 2.0 <span class="inline-formula">µ</span>m (SWIR-2) to coarse spectral resolution, without a further addition of noise, and we evaluate single-band retrievals of the column-averaged dry-air mole fractions of <span class="inline-formula">CO<sub>2</sub></span> (<span class="inline-formula">XCO<sub>2</sub></span>) by comparison to ground truth provided by the Total Carbon Column Observing Network (TCCON) and by comparison to global “native” GOSAT retrievals with native spectral resolution and spectral band selection. Coarsening spectral resolution from GOSAT's native resolving power of <span class="inline-formula">>20 000</span> to the range of 700 to a few thousand makes the scatter of differences between the SWIR-1 and SWIR-2 retrievals and<span id="page732"/> TCCON increase moderately. For resolving powers of 1200 (SWIR-1) and 1600 (SWIR-2), the scatter increases from 2.4 (native) to 3.0 ppm for SWIR-1 and 3.3 ppm for SWIR-2. Coarser spectral resolution yields only marginally worse performance than the native GOSAT configuration in terms of station-to-station variability and geophysical parameter correlations for the GOSAT–TCCON differences. Comparing the SWIR-1 and SWIR-2 configurations to native GOSAT retrievals on the global scale, however, reveals that the coarse-resolution SWIR-1 and SWIR-2 configurations suffer from some spurious correlations with geophysical parameters that characterize the light-scattering properties of the scene such as particle amount, size, height and surface albedo. Overall, the SWIR-1 and SWIR-2 configurations with resolving powers of 1200 and 1600 show promising performance for future sensor design in terms of random error sources while residual errors induced by light scattering along the light path need to be investigated further. Due to the stronger <span class="inline-formula">CO<sub>2</sub></span> absorption bands in SWIR-2 than in SWIR-1, the former has the advantage that measurement noise propagates less into the retrieved <span class="inline-formula">XCO<sub>2</sub></span> and that some retrieval information on particle scattering properties is accessible.</p>https://www.atmos-meas-tech.net/13/731/2020/amt-13-731-2020.pdf |
| spellingShingle | J. S. Wilzewski J. S. Wilzewski A. Roiger J. Strandgren J. Landgraf D. G. Feist D. G. Feist D. G. Feist V. A. Velazco N. M. Deutscher I. Morino H. Ohyama Y. Té R. Kivi T. Warneke J. Notholt M. Dubey R. Sussmann M. Rettinger F. Hase K. Shiomi A. Butz Spectral sizing of a coarse-spectral-resolution satellite sensor for XCO<sub>2</sub> Atmospheric Measurement Techniques |
| title | Spectral sizing of a coarse-spectral-resolution satellite sensor for XCO<sub>2</sub> |
| title_full | Spectral sizing of a coarse-spectral-resolution satellite sensor for XCO<sub>2</sub> |
| title_fullStr | Spectral sizing of a coarse-spectral-resolution satellite sensor for XCO<sub>2</sub> |
| title_full_unstemmed | Spectral sizing of a coarse-spectral-resolution satellite sensor for XCO<sub>2</sub> |
| title_short | Spectral sizing of a coarse-spectral-resolution satellite sensor for XCO<sub>2</sub> |
| title_sort | spectral sizing of a coarse spectral resolution satellite sensor for xco sub 2 sub |
| url | https://www.atmos-meas-tech.net/13/731/2020/amt-13-731-2020.pdf |
| work_keys_str_mv | AT jswilzewski spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT jswilzewski spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT aroiger spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT jstrandgren spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT jlandgraf spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT dgfeist spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT dgfeist spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT dgfeist spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT vavelazco spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT nmdeutscher spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT imorino spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT hohyama spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT yte spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT rkivi spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT twarneke spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT jnotholt spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT mdubey spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT rsussmann spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT mrettinger spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT fhase spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT kshiomi spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub AT abutz spectralsizingofacoarsespectralresolutionsatellitesensorforxcosub2sub |