Full-resolution sunlight measured at top of atmosphere (Envisat)
What it measures. How much light the sensor recorded at the top of the atmosphere, across 15 selectable color bands from visible to near-infrared, at full 300-meter detail and full image width.
How it's made. Collected by the MERIS instrument on Europe's Envisat satellite (which operated 2002 to 2012), then geolocated and calibrated as a Level-1 radiance product in a 2020 reprocessing.
How & where you'd use it. A calibrated starting point for studying ocean color, land, and atmosphere. Most people use the higher-level products built from it rather than the raw radiance directly.
What's measured
Coverage & cadence
- Time span2002-05-17 → 2012-04-08
- Measured byENVISAT (MERIS)
- Processing levelLevel 1B
- Spatial extent-180, -90, 180, 90
- FormatsnetCDF-4
- StatusCOMPLETE
What you can do with it
- Map air pollutants — NO₂, aerosols, ozone
- Track greenhouse gases and Earth's energy budget
- Feed weather and air-quality analysis
Official description
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_FRS_1P is the short-name for the MERIS Level-1 full resolution, full swath, geolocated and calibrated top-of-atmosphere (TOA) radiance product. This product contains the TOA upwelling spectral radiance measurements. 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.
Get the data
import earthaccess
earthaccess.login(strategy="netrc") # free Earthdata Login
results = earthaccess.search_data(
short_name="EN1_MDSI_MER_FRS_1P",
version="4",
bounding_box=(-122.5, 37.2, -121.8, 37.9), # your area (W,S,E,N)
temporal=("2024-01-01", "2024-12-31"), # your dates
)
files = earthaccess.open(results) # stream straight from LAADSBrowsing CMR needs no login. Downloading or streaming bytes needs a free Earthdata Login + the earthaccess package.