Atmospheric correction of the ocean color observations of the medium resolution imaging spectrometer (MERIS)

1997 ◽  
Author(s):  
David Antoine ◽  
Andre Morel
Keyword(s):  
Ocean Color ◽  
Atmospheric Correction ◽  
Imaging Spectrometer ◽  
Medium Resolution ◽  
Resolution Imaging

scholarly journals Evaluation of MERIS products from Baltic Sea coastal waters rich in CDOM

Ocean Science ◽  
2014 ◽  
Vol 10 (3) ◽  
pp. 377-396 ◽  
Author(s):  
J. M. Beltrán-Abaunza ◽  
S. Kratzer ◽  
C. Brockmann
Keyword(s):  
Coastal Waters ◽  
Atmospheric Correction ◽  
Processing Algorithm ◽  
Imaging Spectrometer ◽  
Ground Segment ◽  
Suspended Particulate ◽  
Medium Resolution ◽  
University Of Berlin ◽  
Resolution Imaging ◽  
Chlorophyll Concentrations

Abstract. In this study, retrievals of the medium resolution imaging spectrometer (MERIS) reflectances and water quality products using four 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, improves 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), data dispersion dominated in the retrievals with the MEGS (MERIS ground segment processor) processor. The lowest bias and data dispersion were obtained with MEGS for suspended particulate matter, for which overestimations in the 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 the presence of high CDOM attenuation.

scholarly journals 1-D-Var retrieval of daytime total columnar water vapour from MERIS measurements

2011 ◽  
Vol 4 (6) ◽  
pp. 6811-6844 ◽  
Author(s):  
R. Lindstrot ◽  
R. Preusker ◽  
H. Diedrich ◽  
L. Doppler ◽  
R. Bennartz ◽  
...  
Keyword(s):  
Water Vapour ◽  
Root Mean Square ◽  
Atmospheric Correction ◽  
Mean Square ◽  
Imaging Spectrometer ◽  
Atmospheric Scattering ◽  
Full Resolution ◽  
Medium Resolution ◽  
Correction Scheme ◽  
Resolution Imaging

Abstract. A new scheme for the retrieval of total columnar water vapour from measurements of MERIS (Medium Resolution Imaging Spectrometer) on ENVISAT (ENVIronmental SATellite) is presented. The algorithm is based on a fast forward model of the water vapour transmittance around 900 nm, including a correction for atmospheric scattering. It provides the water vapour column amount for cloud-free scenes above land and ocean at a spatial resolution of 0.25 km × 0.3 km and 1 km × 1.2 km, depending on whether applied to the "full resolution" or the operational "reduced resolution" mode of MERIS. Uncertainties are provided on a pixel-by-pixel basis, taking into account all relevant sources of error. An extensive validation against various sources of ground-based reference data reveals a high accuracy of MERIS water vapour above land (root mean square deviations between 1 mm and 2.7 mm), apart from a wet bias of MERIS between 5 and 10% that is found in all comparison studies. This wet bias might be caused by spectroscopic uncertainties, such as the description of the water vapour continuum. Above ocean the accuracy is reduced, due to the uncertainty introduced by the unknown atmospheric scattering. Consequently, an increased root mean square deviation of ≥5 mm was found by comparing MERIS total columnar water vapour above ocean against SSM/I and ENVISAT MWR data. An increased wet bias of 2–3 mm is found over ocean, potentially du to a not properly working atmospheric correction scheme.

scholarly journals Evaluation of the MERIS aerosol product over land with AERONET

2008 ◽  
Vol 8 (1) ◽  
pp. 3721-3759 ◽  
Author(s):  
J. Vidot ◽  
R. Santer ◽  
O. Aznay
Keyword(s):  
Optical Properties ◽  
Surface Reflectance ◽  
Aerosol Optical Properties ◽  
Simple Criterion ◽  
Imaging Spectrometer ◽  
Inherent Optical Properties ◽  
Look Up Table ◽  
Medium Resolution ◽  
Reflectance Model ◽  
Resolution Imaging

Abstract. The Medium Resolution Imaging Spectrometer (MERIS) launched in February 2002 on-board the ENVISAT spacecraft is making global observations of top-of-atmosphere (TOA) radiances. Aerosol optical properties are retrieved over land using Look-Up Table (LUT) based algorithm and surface reflectances in the blue and the red spectral regions. We compared instantaneous aerosol optical thicknesses retrieved by MERIS in the blue and the red at locations containing sites within the Aerosol Robotic Network (AERONET). Between 2002 and 2005, a set of 500 MERIS images were used in this study. The result shows that, over land, MERIS aerosol optical thicknesses are well retrieved in the blue and poorly retrieved in the red, leading to an underestimation of the Angstrom coefficient. Correlations are improved by applying a simple criterion to avoid scenes probably contaminated by thin clouds. To investigate the weakness of the MERIS algorithm, ground-based radiometer measurements have been used in order to retrieve new aerosol models, based on their Inherent Optical Properties (IOP). These new aerosol models slightly improve the correlation, but the main problem of the MERIS aerosol product over land can be attributed to the surface reflectance model in the red.

Medium-Resolution Imaging Spectrometer (MERIS) calibration sequence

1996 ◽  
Author(s):  
Gilles Baudin ◽  
Steven Matthews ◽  
Richard Bessudo ◽  
Jean-Loup Bezy
Keyword(s):  
Imaging Spectrometer ◽  
Medium Resolution ◽  
Resolution Imaging

Studying Chlorophyll-A Concentration of Bosten Lake (Xinjiang, Northwest China) by MERIS Data

2013 ◽  
Vol 864-867 ◽  
pp. 2750-2755
Author(s):  
Ying Liu ◽  
An Ming Bao ◽  
Xi Chen
Keyword(s):  
Spatial Distribution ◽  
Chlorophyll A ◽  
Field Data ◽  
Northwest China ◽  
Imaging Spectrometer ◽  
Boundary Area ◽  
Bosten Lake ◽  
Medium Resolution ◽  
Resolution Imaging ◽  
Chla Concentration

The Chlorophyll-a (Chla) concentration in Bosten Lake was estimated and mapped using the data of the Medium Resolution Imaging Spectrometer (MERIS) on board the ENVIronmental SATellite (ENVISAT) platform. The fixed aerosol option was chosen and local aerosol optical thickness was used in SeaDAS. The Chla concentration was retrieved by the OC3E algorithm and verified by Field data with high correlation coefficient of 0.79. It showed strong horizontal heterogeneities, which is high at the Huangshuigou region, mediate along the boundary area, and low at the middle of the lake, and decreases from the boundary to the center of the Lake. Its spatial distribution is controlled by the location of inlet and outlet and the type and quantity of discharging around the lake. On sep. 22, 2010, its value is up to 10.98 mg m-3. The minimum, maximum, average and median value of Chla concentration on Aug. 6, 2011 from MERIS data in Bosten Lake is 2.72, 8.93, 3.90 and 3.69 mg m-3.

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