The polarized Sun and sky radiometer SSARA: design, calibration, and application for ground-based aerosol remote sensing
Recently, polarimetry has been used to enhance classical photometry to infer aerosol optical properties, as polarized radiation contains additional information about the particles. Therefore, we have equipped the Sun-sky automatic radiometer (SSARA) with polarizer filters to measure linearly polariz...
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Ludwig-Maximilians-Universität München
2020
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ftmuenchenepub:oai:epub.ub.uni-muenchen.de:89631 2023-05-15T13:06:13+02:00 The polarized Sun and sky radiometer SSARA: design, calibration, and application for ground-based aerosol remote sensing Grob, Hans Emde, Claudia Wiegner, Matthias Seefeldner, Meinhard Forster, Linda Mayer, Bernhard 2020-01-01 application/pdf https://epub.ub.uni-muenchen.de/89631/1/amt-13-239-2020.pdf https://epub.ub.uni-muenchen.de/89631/ http://nbn-resolving.de/urn:nbn:de:bvb:19-epub-89631-8 https://doi.org/10.5194/amt-13-239-2020 eng eng Ludwig-Maximilians-Universität München Grob, Hans; Emde, Claudia; Wiegner, Matthias; Seefeldner, Meinhard; Forster, Linda; Mayer, Bernhard (2020): The polarized Sun and sky radiometer SSARA: design, calibration, and application for ground-based aerosol remote sensing. In: Atmospheric Measurement Techniques, Vol. 13, Nr. 1: S. 239-258 [PDF, 9MB] https://epub.ub.uni-muenchen.de/89631/1/amt-13-239-2020.pdf http://nbn-resolving.de/urn:nbn:de:bvb:19-epub-89631-8 https://epub.ub.uni-muenchen.de/89631/ doi:10.5194/amt-13-239-2020 Atmospheric Measurement Techniques Physik ddc:530 doc-type:article Zeitschriftenartikel NonPeerReviewed 2020 ftmuenchenepub https://doi.org/10.5194/amt-13-239-2020 2022-11-28T00:27:15Z Recently, polarimetry has been used to enhance classical photometry to infer aerosol optical properties, as polarized radiation contains additional information about the particles. Therefore, we have equipped the Sun-sky automatic radiometer (SSARA) with polarizer filters to measure linearly polarized light at 501.5 nm. We describe an improved radiometric and polarimetric calibration method, which allows us to simultaneously determine the linear polarizers' diattenuation and relative orientation with high accuracy (0.002 and 0.1 degrees, respectively). Furthermore, we employed a new calibration method for the alt-azimuthal mount capable of correcting the instrument's pointing to within 32 arcmin. So far, this is limited by the accuracy of the Sun tracker. Both these methods are applicable to other Sun and sky radiometers, such as the Cimel CE318-DP instruments used in the AErosol RObotic NETwork (AERONET). During the A-LIFE (Absorbing aerosol layers in a changing climate: aging, LIFEtime and dynamics) field campaign in April 2017, SSARA collected 22 d of data. Here, we present two case studies. The first demonstrates the performance of an aerosol retrieval from SSARA observations under partially cloudy conditions. In the other case, a high aerosol load due to a Saharan dust layer was present during otherwise clear-sky conditions. Article in Journal/Newspaper Aerosol Robotic Network Open Access LMU (Ludwig-Maximilians-University Munich) Atmospheric Measurement Techniques 13 1 239 258 |
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Open Access LMU (Ludwig-Maximilians-University Munich) |
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ftmuenchenepub |
language |
English |
topic |
Physik ddc:530 |
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Physik ddc:530 Grob, Hans Emde, Claudia Wiegner, Matthias Seefeldner, Meinhard Forster, Linda Mayer, Bernhard The polarized Sun and sky radiometer SSARA: design, calibration, and application for ground-based aerosol remote sensing |
topic_facet |
Physik ddc:530 |
description |
Recently, polarimetry has been used to enhance classical photometry to infer aerosol optical properties, as polarized radiation contains additional information about the particles. Therefore, we have equipped the Sun-sky automatic radiometer (SSARA) with polarizer filters to measure linearly polarized light at 501.5 nm. We describe an improved radiometric and polarimetric calibration method, which allows us to simultaneously determine the linear polarizers' diattenuation and relative orientation with high accuracy (0.002 and 0.1 degrees, respectively). Furthermore, we employed a new calibration method for the alt-azimuthal mount capable of correcting the instrument's pointing to within 32 arcmin. So far, this is limited by the accuracy of the Sun tracker. Both these methods are applicable to other Sun and sky radiometers, such as the Cimel CE318-DP instruments used in the AErosol RObotic NETwork (AERONET). During the A-LIFE (Absorbing aerosol layers in a changing climate: aging, LIFEtime and dynamics) field campaign in April 2017, SSARA collected 22 d of data. Here, we present two case studies. The first demonstrates the performance of an aerosol retrieval from SSARA observations under partially cloudy conditions. In the other case, a high aerosol load due to a Saharan dust layer was present during otherwise clear-sky conditions. |
format |
Article in Journal/Newspaper |
author |
Grob, Hans Emde, Claudia Wiegner, Matthias Seefeldner, Meinhard Forster, Linda Mayer, Bernhard |
author_facet |
Grob, Hans Emde, Claudia Wiegner, Matthias Seefeldner, Meinhard Forster, Linda Mayer, Bernhard |
author_sort |
Grob, Hans |
title |
The polarized Sun and sky radiometer SSARA: design, calibration, and application for ground-based aerosol remote sensing |
title_short |
The polarized Sun and sky radiometer SSARA: design, calibration, and application for ground-based aerosol remote sensing |
title_full |
The polarized Sun and sky radiometer SSARA: design, calibration, and application for ground-based aerosol remote sensing |
title_fullStr |
The polarized Sun and sky radiometer SSARA: design, calibration, and application for ground-based aerosol remote sensing |
title_full_unstemmed |
The polarized Sun and sky radiometer SSARA: design, calibration, and application for ground-based aerosol remote sensing |
title_sort |
polarized sun and sky radiometer ssara: design, calibration, and application for ground-based aerosol remote sensing |
publisher |
Ludwig-Maximilians-Universität München |
publishDate |
2020 |
url |
https://epub.ub.uni-muenchen.de/89631/1/amt-13-239-2020.pdf https://epub.ub.uni-muenchen.de/89631/ http://nbn-resolving.de/urn:nbn:de:bvb:19-epub-89631-8 https://doi.org/10.5194/amt-13-239-2020 |
genre |
Aerosol Robotic Network |
genre_facet |
Aerosol Robotic Network |
op_source |
Atmospheric Measurement Techniques |
op_relation |
Grob, Hans; Emde, Claudia; Wiegner, Matthias; Seefeldner, Meinhard; Forster, Linda; Mayer, Bernhard (2020): The polarized Sun and sky radiometer SSARA: design, calibration, and application for ground-based aerosol remote sensing. In: Atmospheric Measurement Techniques, Vol. 13, Nr. 1: S. 239-258 [PDF, 9MB] https://epub.ub.uni-muenchen.de/89631/1/amt-13-239-2020.pdf http://nbn-resolving.de/urn:nbn:de:bvb:19-epub-89631-8 https://epub.ub.uni-muenchen.de/89631/ doi:10.5194/amt-13-239-2020 |
op_doi |
https://doi.org/10.5194/amt-13-239-2020 |
container_title |
Atmospheric Measurement Techniques |
container_volume |
13 |
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1 |
container_start_page |
239 |
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258 |
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1765996623365668864 |