Reduced Resolution Geolocated and Calibrated TOA Radiance

The Medium Resolution Imaging Spectrometer (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. 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. The 4th reprocessing cycle, in 2020, has produced both the full-resolution and reduced-resolution L1 and L2 MERIS products. EN1_MDSI_MER_RR__1P is the short-name for the MERIS Level-1 reduced resolution, geolocated and calibrated top-of-atmosphere (TOA) radiance product. This product contains the TOA upwelling spectral radiance measurements at reduced resolution. The in-band reference irradiances for the 15 MERIS bands are computed by averaging the in-band solar irradiance for each pixel. Each pixel’s in-band solar irradiance is computed by integrating the reference solar spectrum with the band-pass of each pixel. The Level-1 product contains 22 data files: 15 files contain radiances for each band (one band per file) along with associated error estimates, and 7 annotation data files. It also includes a Manifest file that provides metadata information describing the product.

Data and Resources

Additional Info

Field Value
Maintainer Earthdata Forum
Last Updated May 11, 2026, 21:43 (UTC)
Created April 1, 2025, 18:30 (UTC)
accessLevel public
bureauCode {026:00}
catalog_conformsTo https://project-open-data.cio.gov/v1.1/schema
harvest_object_id 95e2b5c5-1b1d-4223-a5f0-a2a4b2ac49b9
harvest_source_id b99e41c6-fe79-4c19-bbc3-9b6c8111bfac
harvest_source_title Science Discovery Engine
identifier 10.5270/EN1-opsw96m
license https://www.usa.gov/government-works
modified 2026-05-04T22:16:01Z
programCode {026:000}
publisher NASA/GSFC/SED/ESD/HBSL/BISB/LAADS
resource-type Dataset
source_datajson_identifier true
source_hash 1beddf4685109e6e5de07b875896df5b0491c67f5ff72893ae7aab7fb9c7103b
source_schema_version 1.1
spatial ["CARTESIAN",[{"NorthBoundingCoordinate":90.0,"WestBoundingCoordinate":-180.0,"EastBoundingCoordinate":180.0,"SouthBoundingCoordinate":-90.0}]]
temporal 2002-04-29/2012-04-08
theme {"Earth Science"}