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| Titel |
Haze compensation and atmospheric correction for Sentinel-2 data |
| VerfasserIn |
Aliaksei Makarau, Rudolf Richter  , Viktoria Zekoll, Peter Reinartz |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250126087
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| Publikation (Nr.) |
 EGU/EGU2016-5766.pdf |
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| Zusammenfassung |
| Sentinel-2 data offer the opportunity to analyse landcover at a high
spatial accuracy together with a wide swath. Nevertheless, the high data
volume requires a per granule analysis. This may lead to border effects
(difference in the radiance/reflectance values) between the neighbouring
granules during atmospheric correction. Especially in case of high variations of
the aerosol optical thickness (AOT) across the granules, especially in
case of haze, the atmospherically corrected mosaicked products often
show granule border effects.
To overcome these artefacts a dehazing prior to the atmospheric correction is
performed. The dehazing compensates only for the haze thickness keeping
the AOT fraction for further estimation and compensation in the
atmospheric correction chain. This approach results in a smoother AOT
map estimate and a corresponding bottom of atmosphere (BOA) reflectance
with low or no border artefacts.
Using digital elevation models (DEMs) allows a better labelling of
haze and a higher accuracy of the dehazing. The DEM analysis rejects
high elevation areas where bright surfaces might erroneously be
classified as haze, thus reducing the probability of misclassification.
The dehazing and atmospheric correction are implemented in the DLR's
ATCOR software. An example of a numeric evaluation of atmospheric correction
products (AOT and BOA reflectance) is given. It demonstrates a smooth
transition between the granules in the AOT map leading to a proper
estimate of the BOA reflectance data. |
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