Reflectances transect from coast to open sea, Baltic Sea

Fuente: PANGAEA
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Beltrán-Abaunza, José M, Kratzer, Susanne, Brockmann, Carsten
Format: Dataset Open Access
Langue:en
Publié: PANGAEA 2014
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1867170972233105408
author Beltrán-Abaunza, José M
Kratzer, Susanne
Brockmann, Carsten
author_facet Beltrán-Abaunza, José M
Kratzer, Susanne
Brockmann, Carsten
collection Datos científicos de ciencias marinas y ambientales
contents In this study, retrievals of the medium resolution imaging spectrometer (MERIS) reflectances and water quality products using 4 different coastal processing algorithms freely available are assessed by comparison against sea-truthing data. The study is based on a pair-wise comparison using processor-dependent quality flags for the retrieval of valid common macro-pixels. This assessment is required in order to ensure the reliability of monitoring systems based on MERIS data, such as the Swedish coastal and lake monitoring system (http.vattenkvalitet.se). The results show that the pre-processing with the Improved Contrast between Ocean and Land (ICOL) processor, correcting for adjacency effects, improve the retrieval of spectral reflectance for all processors, Therefore, it is recommended that the ICOL processor should be applied when Baltic coastal waters are investigated. Chlorophyll was retrieved best using the FUB (Free University of Berlin) processing algorithm, although overestimations in the range 18-26.5%, dependent on the compared pairs, were obtained. At low chlorophyll concentrations (< 2.5 mg/m**3), random errors dominated in the retrievals with the MEGS (MERIS ground segment processor) processor. The lowest bias and random errors were obtained with MEGS for suspended particulate matter, for which overestimations in te range of 8-16% were found. Only the FUB retrieved CDOM (Coloured Dissolved Organic Matter) correlate with in situ values. However, a large systematic underestimation appears in the estimates that nevertheless may be corrected for by using a~local correction factor. The MEGS has the potential to be used as an operational processing algorithm for the Himmerfjärden bay and adjacent areas, but it requires further improvement of the atmospheric correction for the blue bands and better definition at relatively low chlorophyll concentrations in presence of high CDOM attenuation.
format Dataset Open Access
id pangaea_https___doi_org_10_1594_PANGAEA_831721
institution PANGAEA
language en
publishDate 2014
publisher PANGAEA
record_format pangaea
spellingShingle Reflectances transect from coast to open sea, Baltic Sea
Beltrán-Abaunza, José M
Kratzer, Susanne
Brockmann, Carsten
DATE/TIME; Difference; Distance; Himmerfjaerden; Himmerfjärden, Stockholm archipelago, Sweden; LATITUDE; LONGITUDE; Number string
In this study, retrievals of the medium resolution imaging spectrometer (MERIS) reflectances and water quality products using 4 different coastal processing algorithms freely available are assessed by comparison against sea-truthing data. The study is based on a pair-wise comparison using processor-dependent quality flags for the retrieval of valid common macro-pixels. This assessment is required in order to ensure the reliability of monitoring systems based on MERIS data, such as the Swedish coastal and lake monitoring system (http.vattenkvalitet.se). The results show that the pre-processing with the Improved Contrast between Ocean and Land (ICOL) processor, correcting for adjacency effects, improve the retrieval of spectral reflectance for all processors, Therefore, it is recommended that the ICOL processor should be applied when Baltic coastal waters are investigated. Chlorophyll was retrieved best using the FUB (Free University of Berlin) processing algorithm, although overestimations in the range 18-26.5%, dependent on the compared pairs, were obtained. At low chlorophyll concentrations (< 2.5 mg/m**3), random errors dominated in the retrievals with the MEGS (MERIS ground segment processor) processor. The lowest bias and random errors were obtained with MEGS for suspended particulate matter, for which overestimations in te range of 8-16% were found. Only the FUB retrieved CDOM (Coloured Dissolved Organic Matter) correlate with in situ values. However, a large systematic underestimation appears in the estimates that nevertheless may be corrected for by using a~local correction factor. The MEGS has the potential to be used as an operational processing algorithm for the Himmerfjärden bay and adjacent areas, but it requires further improvement of the atmospheric correction for the blue bands and better definition at relatively low chlorophyll concentrations in presence of high CDOM attenuation.
title Reflectances transect from coast to open sea, Baltic Sea
topic DATE/TIME; Difference; Distance; Himmerfjaerden; Himmerfjärden, Stockholm archipelago, Sweden; LATITUDE; LONGITUDE; Number string
url https://doi.org/10.1594/PANGAEA.831721