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Reference documents
MERIS Product Handbook
MERIS Product Handbook
MERIS Product Handbook
MERIS Credits
MERIS Data Formats Products
MERIS Glossary and reference documents
Optics Glossary
Vegetation Glossary
Water Vapour Glossary
Ocean Colour Glossary
Neural Network Glossary
Meteorology Glossary
Cloud Glossary
Atmosphere Glossary
Product Glossary
Geometry Glossary
Acronyms and Abbreviations
MERIS Instrument
Instrument Characteristics and Performance
MERIS Quality Status
Instrument characteristic
Characterisation and Calibration
Onboard Calibration Hardware
Calibration Modes
Instrument Description
Instrument model philosophy
Instrument Concept
Digital processing Unit
Video Electronic Unit
Detection Focal Plane
Instrument optics
The MERIS instrument
MERIS Products and Algorithms
Auxiliary Files
Common Auxiliary Datasets
Auxiliary Datasets for Level 2 Processing
Auxiliary Datasets for Level 1b Processing
Summary of Auxiliary Datasets
Water Vapour Parameters Data File
Atmosphere Parameters Data File
Level 2 Control Parameters Data File
Aerosol Climatology Data File
Coastline/Land/Ocean Data File
Digital Roughness Model Data File
Radiometric Calibration Data File
MERIS Level 1b Control Parameters Data File
Digital Elevation Model
ECMWF Data Files
ENVISAT Orbit Data Files
Surface Confidence Map File
Land Vegetation Index Parameters Data File
Cloud Measurement Parameters Data File
Ocean II Parameters Data File
Ocean I Parameters Data File
Land Aerosols Parameters Data File
Ocean Aerosols Parameters Data File
MERIS Instrument Data File
MERIS-Specific Topics
Level 2 Products and Algorithms
Level 2 Products
Level 2 Geophysical Products
Annotation data set
Water Vapour products
Land products
Meris Terrestrial Chlorophyll Index
Meris Global Vegetation Index
Aerosol Angström Coefficient
Aerosol optical thickness
Cloud products
Cloud reflectance
Cloud Type
Cloud top pressure
Cloud albedo
Cloud optical thickness
Ocean products
The MERIS Aerosol Angström Coefficient
Aerosol optical thickness
Photosynthetically Active Radiation (PAR)
Yellow substance
Suspended matter
Algal Pigment Index II
Algal Pigment Index I
Normalized water leaving radiance / reflectance
Product description
Level 2 High-Level Organisation of Products
Full Resolution Geophysical Product
Extracted Vegetation Indices
Extracted Cloud Thickness and Water Vapour for Meteo Users
Extracted Cloud Thickness and Water Vapour
Reduced Resolution Geophysical Product
Level 2 Algorithms
Level 2 Accuracies
Level 2 Algorithm Description
MERIS Level 2 Product Formatting Algorithm
Measurement Data Sets
Annotation Data Set "Tie Points Location and corresponding Auxiliary Data"
Global Annotation Data Set - Scaling Factors
Annotation Data Set "Summary Product Quality"
Specific Product Header
Main Product Header
MERIS Land Pixels Processing
MERIS Bottom Of Atmosphere Vegetation Index (BOAVI) (step 2.8)
Atmospheric correction over land (step 2.6.23)
MERIS Top Of Atmosphere Vegetation Index (TOAVI) (step 2.2)
Water Processing
MERIS Ocean Colour Processing (step 2.9)
Clear water atmospheric corrections (step 2.6.9)
Turbid water screening and corrections (steps 2.6.8, 2.6.10)
Water Confidence Checks (step 2.6.5)
Cloud Processing
Cloud type processing (step 2.4.8)
Cloud Optical Thickness processing (step 2.4.3)
Cloud Albedo processing (step 2.4.1)
Total Water Vapour Retrieval
Water vapour polynomial (function)
Range checks (steps 2.3.0, 2.3.6)
Water vapour retrieval over clouds (step 2.3.3)
Water vapour retrieval over water surfaces (steps 2.3.2, 2.3.5)
Water vapour retrieval over land surfaces (step 2.3.1)
MERIS Pixel Identification
Land Identification (step 2.6.26) and Smile Effect Correction (step 2.1.6)
Gaseous absorption corrections (step 2.6.12)
Stratospheric Aerosol Correction (step 2.1.9)
Cloud screening (steps 2.1.2, 2.1.7, 2.1.8)
MERIS Pressure Processing
Atmospheric pressure confidence tests (steps 2.1.2)
Atmospheric pressure estimate (steps 2.1.5, 2.1.12)
MERIS Pre-processing
Pre processing step
Level 1b product check
Level 2 Physical Justification
Level 1b Products and Algorithms
Level 1b product definition
Browse Products
Level 1b Essential Product Confidence Data
Level 1b Engineering Quantities
Level 1b Accuracies
Level 1b High-Level Organisation of Products
Measurement Data Sets
Annotation Data Set "Product Quality"
Annotation Data Set "Tie Points Location and corresponding Auxiliary Data"
Global Annotation Data Set
Specific Product Header
Main Product Header
Full Resolution Geolocated and Calibration TOA Radiance
Reduced Resolution Geolocated and Calibration TOA Radiance
Level 1b Algorithms
External Data Assimilation
Pixel Classification
Stray Light Correction
Radiometric Processing
Saturated Pixels
Source Data Packet Extraction
Level 0 Products
Product Evolution History
Definitions and Conventions
Notations and Conventions
Product Grid
Organisation of Products
MERIS product data structure
File naming convention
Acquisition identification scheme
Product identification scheme
Latency, Throughput and Data Volume
MERIS products overview
MERIS product types
Full and reduced resolutions
MERIS product processing levels
MERIS User Guide
Image gallery
How to Use MERIS Data
Software Tools
General Tools
How to Choose MERIS Data
Summary of Applications vs. Products
Special Features of MERIS
Geographical Coverage
Principles of Measurement
Scientific Background
Mission Objectives
MERIS Level 3 products
Geophysical Measurements
MERIS Product Handbook
Site Map
Frequently asked questions
Terms of use
Contact us


1.1.5 Special Features of MERIS

The global mission of AATSR and MERIS make a major contribution to understanding the role of the oceans and ocean productivity in the climate system, and enhance our ability to forecast change through models. Both sensors offer a large synergistic potential that contributes to climate studies and global change observations in addressing environmental features in a multi-disciplinary way.

MERIS, primarily dedicated to observing oceanic biology and marine water quality through observations of water colour, makes also contributions to atmospheric and land surface related studies. AATSR has, besides its main objective to provide detailed sea surface temperature maps, the capability to measure a range of parameters for cloud microphysics, plus land surface temperature and various vegetation indices over land.

MERIS provides a unique European remote sensing capability for observing oceanic biology and marine water quality through global observations of ocean colour (figure 1.6), and provides continuity with other ocean colour sensors such as SeaWiFS and MODIS. AATSR provides continuity with similar ATSR instruments flown on ERS-1 and -2 ensuring the production of a near-continuous 15-year dataset of sea surface temperatures (SST) at an unprecedented accuracy level of 0.3 K or better (figure 1.7).

Figure 1.8 - Global ocean colour image

Figure 1.9 - An ATSR-2 11 µm brightness temperature image of the Gulf of California.

The hottest areas (shown in grey) are mostly land. The cooler sea surface temperatures are shown using purple (coolest) to red (warmest). Source: RAL (file: california_sst.gif).

Biogenic material in our oceans accounts for a large portion of their carbon pickup, playing a major role in the Earth's carbon cycle and therefore our climate. Sea surface temperature is one of the most stable of several geographical variables, which, when determined globally, characterize the state of the Earth's climate system. Phytoplankton concentrations in the oceans, responsible for the oceans' primary production, need to be known with a high degree of accuracy for their adequate prediction through modelling. Furthermore, the accurate knowledge of marine water constituent concentrations, has become mandatory for the assessment of the water quality in marine ecosystems. In parallel, the precise measurement of small changes in SST provides an indication of significant variations in ocean/atmosphere heat transfer rates and their impact on our physical climate.

AATSR and MERIS are both passive optical imaging instruments measuring radiation reflected and emitted from the Earth's surface. AATSR has 4 channels in the visible/near infrared wavelengths and 3 channels in the thermal infrared region. MERIS has 15 channels in the visible and near infrared (see table 1.1 below). The overlap between the instrument bands and the complementary measurements they provide over ocean and land, create novel opportunities for synergetic use of data in many fields of study.

Table 1.1 - MERIS spectral bands and applications.


Band centre

Band width





Yellow substance and detrital pigments




Chlorophyll absorption maximum




Chlorophyll and other pigments




Suspended sediment, red tides




Chlorophyll absorption minimum




Suspended sediment




Chlorophyll absorption & fluorescence reference




Chlorophyll fluorescence peak




Fluorescence reference, atmosphere corrections




Vegetation, cloud, O2 absoption band reference




O2 R- branch absorption band




Atmosphere corrections




Atmosphere corrections




Vegetation, water vapour reference




Water vapour

This fixed set of bands was recommended by the Science Advisory Group (SAG). The level 2 ESA products have been validated for this set of bands.

The detailed spectral response of each band in each camera is given in document “MERIS Spectral Characterisation” ( R-10).

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry