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<front>
<journal-meta>
<journal-id journal-id-type="publisher">EGUsphere</journal-id>
<journal-title-group>
<journal-title>EGUsphere</journal-title>
<abbrev-journal-title abbrev-type="publisher">EGUsphere</abbrev-journal-title>
<abbrev-journal-title abbrev-type="nlm-ta">EGUsphere</abbrev-journal-title>
</journal-title-group>
<issn pub-type="epub"></issn>
<publisher><publisher-name>Copernicus Publications</publisher-name>
<publisher-loc>Göttingen, Germany</publisher-loc>
</publisher>
</journal-meta>
<article-meta>
<article-id pub-id-type="doi">10.5194/egusphere-2025-1282</article-id>
<title-group>
<article-title>First results of the XBAER aerosol optical depth algorithm with EnMAP data</article-title>
</title-group>
<contrib-group><contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Laffoy</surname>
<given-names>Simon</given-names>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Vountas</surname>
<given-names>Marco</given-names>
<ext-link>https://orcid.org/0000-0002-0297-5974</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Mei</surname>
<given-names>Linlu</given-names>
</name>
<xref ref-type="aff" rid="aff2">
<sup>2</sup>
</xref>
<xref ref-type="aff" rid="aff3">
<sup>3</sup>
</xref>
</contrib>
<contrib contrib-type="author" xlink:type="simple"><name name-style="western"><surname>Bösch</surname>
<given-names>Hartmut</given-names>
<ext-link>https://orcid.org/0000-0003-3944-9879</ext-link>
</name>
<xref ref-type="aff" rid="aff1">
<sup>1</sup>
</xref>
</contrib>
</contrib-group><aff id="aff1">
<label>1</label>
<addr-line>Institute of Environmental Physics, University of Bremen, Bremen, Germany</addr-line>
</aff>
<aff id="aff2">
<label>2</label>
<addr-line>International Research Center of Big Data for Sustainable Development Goals, Beijing, China</addr-line>
</aff>
<aff id="aff3">
<label>3</label>
<addr-line>Key Laboratory of Digital Earth Science, Aerospace Information Research Institute, Chinese Academy of Sciences, Beijing, China</addr-line>
</aff>
<pub-date pub-type="epub">
<day>08</day>
<month>05</month>
<year>2025</year>
</pub-date>
<volume>2025</volume>
<fpage>1</fpage>
<lpage>19</lpage>
<permissions>
<copyright-statement>Copyright: &#x000a9; 2025 Simon Laffoy et al.</copyright-statement>
<copyright-year>2025</copyright-year>
<license license-type="open-access">
<license-p>This work is licensed under the Creative Commons Attribution 4.0 International License. To view a copy of this licence, visit <ext-link ext-link-type="uri"  xlink:href="https://creativecommons.org/licenses/by/4.0/">https://creativecommons.org/licenses/by/4.0/</ext-link></license-p>
</license>
</permissions>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2025/egusphere-2025-1282/">This article is available from https://egusphere.copernicus.org/preprints/2025/egusphere-2025-1282/</self-uri>
<self-uri xlink:href="https://egusphere.copernicus.org/preprints/2025/egusphere-2025-1282/egusphere-2025-1282.pdf">The full text article is available as a PDF file from https://egusphere.copernicus.org/preprints/2025/egusphere-2025-1282/egusphere-2025-1282.pdf</self-uri>
<abstract>
<p>New high-resolution hyper and multispectral satellite instruments enable the retrieval of aerosol optical depth (AOD) at spatial resolutions of tens of meters. The eXtensible Bremen AErosol Retrieval (XBAER) AOD retrieval algorithm has previously been developed for use with Ocean and Land Colour Instrument (OLCI) and MEdium Resolution Imaging Spectrometer (MERIS) radiance data. With the intention of later modifying XBAER to use the full 30 m spatial resolution data from the Hyper-Spectral Imager (HSI) on board the Environmental Mapping and Analysis Program (EnMAP) satellite, the present study investigates how HSI data compare to OLCI data. For the bands of interest, top of atmosphere reflectances generally compare well (&lt;em&gt;R&lt;/em&gt; &amp;gt; 0.9), the intercept of the best fit line is less than 0.05 from the origin, and the slope is less than 0.1 from 1. However exceptions exist and these are explained as the result of differences in the spectral response functions of the instruments in the region of the spectrum around the O2 A-Band absorption feature, or as a result of differences in the viewing geometry of the satellites which produces differing bidirectional reflectance distribution function (BRDF) effects. XBAER is then used to retrieve OLCI and HSI surface reflectance (SRF) and AOD. For SRF the comparison between OLCI and HSI yields &lt;em&gt;R&lt;/em&gt; = 0.953, best fit intercept = 0.003 and best fit slope = 1.082. The respective comparison for AOD yields &lt;em&gt;R&lt;/em&gt; = 0.809, best fit intercept = 0.153 and best fit slope = 0.785. These comparisons are then separated by surface type and insights are gained into the performance of the algorithm. Finally, the unmodified XBAER algorithm is run using the full spatial resolution HSI data. Plumes from biomass-burning are identified in a single scene, and a comparison with AErosol RObotic NETwork (AERONET) AOD is performed for multiple scenes, achieving &lt;em&gt;R&lt;/em&gt; = 0.631. Future modifications to XBAER that would allow it to produce more accurate retrievals at HSI&apos;s spatial resolution are discussed.</p>
</abstract>
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<funding-group>
<award-group id="gs1">
<funding-source>Deutsches Zentrum für Luft- und Raumfahrt</funding-source>
<award-id>50EE2230</award-id>
</award-group>
<award-group id="gs2">
<funding-source>Bundesministerium für Wirtschaft und Klimaschutz</funding-source>
<award-id>50EE2230</award-id>
</award-group>
</funding-group>
</article-meta>
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