Envisat MEdium Resolution Imaging Spectrometer (MERIS)
MERIS is one of 10 sensors deployed in March of 2002 on board the polar-orbiting Envisat-1 environmental research satellite by the European Space Agency (ESA). The MERIS instrument is a moderate-resolution wide field-of-view push-broom imaging spectroradiometer capable of sensing in the 390 nm to 1040 nm spectral range. Being a programmable instrument, it had the unique capability of selectively adjusting the width and location of its 15 bands through ground command. The instrument has a 68.5-degree field of view and a swath width of 1150 meters, providing a global coverage every 3 days at 300 m resolution. The MERIS instrument was primarily designed for measuring ocean color, but its scope of objectives was broadened to serve atmospheric and terrestrial observations as well.
Communication with the Envisat-1 satellite was lost suddenly on the 8th of April, 2012, just weeks after celebrating its 10th year in orbit. All attempts to re-establish contact were unsuccessful, and the end of the mission was declared on May 9th, 2012.
Envisat image products are provided in .n1 format, which is a structured uncompressed raster format with two files, a header (*.hdr) and an image file with the same root name and no file extension. The header file contains the properties of the raster file and the image file contains the raster data. The Geospatial Data Abstraction Library (GDAL) can handle these datasets, as can other COTS software packages and other open-source software tools. Check out ESA’s Tools & Toolboxes page for a number of additional resources.
In order to access MERIS data, you have to complete these two steps:
- Register for an EOSDIS user account through the EOSDIS User Registration System . If you already have an EOSDIS user account, continue to the next step.
- Add authorization for the MERIS data to your EOSDIS user account by accepting the MERIS Terms and Conditions agreement.
As part of the 4th Reprocessing cycle, the following four reprocessed ESA/Envisat MERIS Full Resolution (FR) and Reduced Resolution (RR) data products that range from May 2002 to April 2012 are available.
|Orbit||790 km, 10:00 am. mean local solar time, sun-synchronous, polar|
|Swath Dimensions||1150 km, global coverage every 3 days|
|Weight||8,211 kg (18,100 lb.)|
|Spatial Resolution||Ocean: 1040 m x 1200 m; Land: 260 m x 300 m|
|Data Rate||50 Mbps|
|Field of View||68.5 deg.|
|Wavebands||15 bands selectable across range: 390 nm to 1040 nm
(bandwidth programmable between 2.5 and 30 nm)
|Design Life||5 years|
± Bandwidth (nm)
|1||412.5 ± 10||Yellow substance and detrital pigments|
|2||442.5 ± 10||Chlorophyll absorption maximum|
|3||490 ± 10||Chlorophyll and other pigments|
|4||510 ± 10||Suspended sediment, red tides|
|5||560 ± 10||Chlorophyll absorption minimum|
|6||620 ± 10||Suspended sediment|
|7||665 ± 10||Chlorophyll absorption and fluorescence reference|
|8||681.25 ± 7.5||Chlorophyll fluorescence peak|
|9||708.75 ± 10||Fluorescence reference, atmospheric corrections|
|10||753.75 ± 7.5||Vegetation, cloud|
|11||760.625 ± 3.75||Oxygen absorption R-branch|
|12||778.75 ± 15||Atmosphere corrections|
|13||865 ± 2||Vegetation, water vapour reference|
|14||885 ± 10||Atmosphere corrections|
|15||900 ± 10||Water vapour, land|