Estimating terrestrial gross primary productivity with the Envisat Medium Resolution Imaging Spectrometer (MERIS) Terrestrial Chlorophyll Index (MTCI)

2010 ◽  
Author(s):  
Samuel Almond ◽  
Doreen S. Boyd ◽  
Jadunandan Dash ◽  
Paul J. Curran ◽  
Ross A. Hill ◽  
...  
Keyword(s):  
Primary Productivity ◽  
Gross Primary Productivity ◽  
Imaging Spectrometer ◽  
Medium Resolution ◽  
Resolution Imaging ◽  
Chlorophyll Index

scholarly journals Estimation of Gross Primary Productivity (GPP) Phenology of a Short-Rotation Plantation Using Remotely Sensed Indices Derived from Sentinel-2 Images

2020 ◽  
Vol 12 (13) ◽  
pp. 2104
Author(s):  
Maral Maleki ◽  
Nicola Arriga ◽  
José Miguel Barrios ◽  
Sebastian Wieneke ◽  
Qiang Liu ◽  
...  
Keyword(s):  
Primary Productivity ◽  
Seasonal Pattern ◽  
Vegetation Indices ◽  
Canopy Structure ◽  
Growing Season ◽  
Gross Primary Productivity ◽  
Imaging Spectrometer ◽  
Short Rotation ◽  
Medium Resolution ◽  
Sentinel 2

This study aimed to understand which vegetation indices (VIs) are an ideal proxy for describing phenology and interannual variability of Gross Primary Productivity (GPP) in short-rotation coppice (SRC) plantations. Canopy structure- and chlorophyll-sensitive VIs derived from Sentinel-2 images were used to estimate the start and end of the growing season (SOS and EOS, respectively) during the period 2016–2018, for an SRC poplar (Populus spp.) plantation in Lochristi (Belgium). Three different filtering methods (Savitzky–Golay (SavGol), polynomial (Polyfit) and Harmonic Analysis of Time Series (HANTS)) and five SOS- and EOS threshold methods (first derivative function, 10% and 20% percentages and 10% and 20% percentiles) were applied to identify the optimal methods for the determination of phenophases. Our results showed that the MEdium Resolution Imaging Spectrometer (MERIS) Terrestrial Chlorophyll Index (MTCI) had the best fit with GPP phenology, as derived from eddy covariance measurements, in identifying SOS- and EOS-dates. For SOS, the performance was only slightly better than for several other indices, whereas for EOS, MTCI performed markedly better. The relationship between SOS/EOS derived from GPP and VIs varied interannually. MTCI described best the seasonal pattern of the SRC plantation’s GPP (R2 = 0.52 when combining all three years). However, during the extreme dry year 2018, the Chlorophyll Red Edge Index performed slightly better in reproducing growing season GPP variability than MTCI (R2 = 0.59; R2 = 0.49, respectively). Regarding smoothing functions, Polyfit and HANTS methods showed the best (and very similar) performances. We further found that defining SOS as the date at which the 10% or 20% percentile occurred, yielded the best agreement between the VIs and the GPP; while for EOS the dates of the 10% percentile threshold came out as the best.

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.

scholarly journals XBAER derived aerosol optical thickness from OLCI/Sentinel-3 observation

2017 ◽  
Author(s):  
Linlu Mei ◽  
Vladimir Rozanov ◽  
Marco Vountas ◽  
John P. Burrows ◽  
Andreas Richter
Keyword(s):  
Optical Thickness ◽  
Aerosol Optical Thickness ◽  
Retrieval Algorithm ◽  
Imaging Spectrometer ◽  
Medium Resolution ◽  
New Instrument ◽  
Resolution Imaging ◽  
Haze Episode ◽  
The Impact ◽  
First Time

Abstract. A prolonged pollution haze event occurred in the northeast part of China during December 16–21, 2016. To assess the impact of such events, the amounts and distribution of aerosol particles formed in such events need to be quantified. The newly launched Ocean Land Color Instrument (OLCI) onboard Sentinel-3 is the successor of the MEdium Resolution Imaging Spectrometer (MERIS). It provides measurements of the radiance and reflectance at the top of the atmosphere which can be used to retrieve the Aerosol Optical Thickness (AOT) on both synoptic to global scales. In this paper, the recently developed AOT retrieval algorithm – eXtensible Bremen AErosol Retrieval (XBAER) has been applied to data from the OLCI instrument for the first time to inlustrate the feasibility of transferring XBAER to new instrument. The first global retrieval results show similar patterns as MODIS and MISR aerosol products. The AOT retrieved from OLCI is validated by comparison with AERONET observations and a correlation coefficient of 0.819 and bias (root mean square) of 0.115 is obtained. The haze episode is well-captured by the OLCI-derived AOT product. XBAER is shown to retrieve AOT from the observations of MERIS and OLCI.

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