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    24-Jul-2014
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MERIS Product Handbook
MERIS Product Handbook
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Glossary
Optics Glossary
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Water Vapour Glossary
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Cloud Glossary
Atmosphere Glossary
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Acronyms and Abbreviations
MERIS Instrument
Instrument Characteristics and Performance
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Characterisation and Calibration
Onboard Calibration Hardware
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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
Flags
Water Vapour products
Land products
Meris Terrestrial Chlorophyll Index
Meris Global Vegetation Index
Aerosol Angström Coefficient
Aerosol optical thickness
Reflectance
Cloud products
Cloud reflectance
Cloud Type
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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
Formatting
External Data Assimilation
Pixel Classification
Geolocation
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
Units
Organisation of Products
MERIS product data structure
File naming convention
Acquisition identification scheme
Product identification scheme
Latency, Throughput and Data Volume
Introduction
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
BEAM
EnviView
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How to Choose MERIS Data
Summary of Applications vs. Products
Land
Atmosphere
Oceans
Introduction
Special Features of MERIS
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Principles of Measurement
Scientific Background
Mission Objectives
MERIS Level 3 products
Heritage
Geophysical Measurements
MERIS Product Handbook
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2.1.1.2 Full and reduced resolutions

MERIS data are provided at 3 different levels of processing - Level 0, Level 1, Level 2 - and at 3 different spatial resolutions - Full, Reduced and Low. They may also be sorted and visualised very easily using a browse product (RGB colour coded images of full-resolution data). Child products, including a limited number of measurement data sets, may also be available in reduced and full resolution.

For the same image, a Full-Resolution (FR) image has 4 × 4 more points (pixels) than the same image in Reduced Resolution (RR), and an RR image has 4 × 4 more points (pixels) than the same image in Low Resolution (LR). Accordingly, a pixel in an FR image represents an area of 260 m × 290 m, in an RR image an area of 1,040 m × 1,160 m, and in LR an area of 4,160 m × 4,640 m.

The instrument always takes measurements with full resolution; i.e., 260 m × 290 m ground resolution. Onboard averaging generates the RR images, while LR images are generated in the ground processor by further averaging the RR data.

Full-resolution images can be provided either as scenes or as imagettes. A scene is a half-swath square image. An imagette is a quarter-swath square image.

The different MERIS products primarily hold:

· instrument source packets for a Level 0 Product

· Top Of Atmosphere (TOA) radiances measured in the 15 MERIS bands for a Level 1 product

· geophysical quantities varying according to the underlying surface identified (land, ocean, or clouds) for a Level 2 product.

In addition to the core geophysical data, MERIS Level 1 and Level 2 products contain:

· geometric information to allow the user to locate the image on the Earth's surface

· data describing the Sun and viewing geometry

· additional annotation data such as coastline information

· terrain height

· meteorological data

· scaling factors to allow the user to decode the data from numerical counts to geophysical meaningful values

· flags that address the quality and the validity of the image

The Level 0 products are generated and archived routinely in both RR and FR, whereas the FR MERIS Level 1b and Level 2 products (scenes or imagettes) are generated on request only.

A reduced resolution product contains data on 1,121 columns (1,165 km) with a number of lines that may vary from product to product. An entire orbit is covered with 15,057 reduced resolution lines. A full-resolution product contains data on 2,241 × 2,241 pixels (i.e., 582 km × 650 km) for a scene and 1,153 × 1,153 pixels (i.e., 300 km × 334 km) for an imagette.


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