ForwardInstrument:  3MI 

Instrument details
Acronym 3MI
Full name Multi-viewing Multi-channel Multi-polarisation Imager
Purpose Aerosol, cirrus clouds, Bidirectional Reflectance Distribution Function (BRDF)
Short description

Bi-directionsl viewing, multi-polarisation, 12 narrow-bandwidth channels, VIS, NIR and SWIR, large swath [see detailed characteristics below]

Monitoring and calibration information here
Background

Evolution of POLDER on ADEOS, ADEOS-2 and PARASOL
Scanning Technique

VIS/NIR channels: 520x520 CCD array, each earth’s spot viewed from ~ 14 directions as satellite moves. SWIR channels: 520x256 CCD array, each earth’s spot viewed from ~ 12 directions as satellite moves. 2200 km swath from both CCD's.
Resolution 4 km IFOV
Coverage / Cycle Near-global coverage every day in daylight.
Mass 60 kg Power 80 W Data Rate 6.5 Mbps

 

Providing Agency ESA
Instrument Maturity Backed by strong heritage
Utilization Period: 2025 to 2047
Last update: 2025-05-27
Detailed characteristics

Channel

Central wavelength

Bandwidth

Polarisation

SNR @ specified input

3MI-2b

410 nm

20 nm

Y

200 @ 46.64 W m-2 sr-1 µm-1

3MI-3

443 nm

20 nm

Y

200 @ 56.61W m-2 sr-1 µm-1

3MI-4

490 nm

20 nm

Y

200 @ 57.74 W m-2 sr-1 µm-1

3MI-5

555 nm

20 nm

Y

200 @ 55.24 W m-2 sr-1 µm-1

3MI-6

670 nm

20 nm

Y

200 @ 44.57 W m-2 sr-1 µm-1

3MI -7

763 nm

10 nm

N

200 @ 36.11 W m-2 sr-1 µm-1

3MI -8

765 nm

40 nm

N

200 @ 36.11 W m-2 sr-1 µm-1

3MI -9

865 nm

40 nm

Y

200 @ 28.20 W m-2 sr-1 µm-1

3MI-9a

910 nm

20 nm

N

200 @ 25.18 W m-2 sr-1 µm-1

3MI -10

1370 nm

40 nm

Y

200 @ 10.73 W m-2 sr-1 µm-1

3MI -11

1650 nm

40 nm

Y

200 @ 6.80 W m-2 sr-1 µm-1

3MI -12

2130 nm

40 nm

Y

200 @ 2.50 W m-2 sr-1 µm-1
Satellites this instrument is flying on

Note: a red tag indicates satellites no longer operational, a green tag indicates operational satellites, a blue tag indicates future satellites

Instrument classification
  • Earth observation instrument
  • Passive optical radiometer or spectrometer
  • Moderate resolution optical imager
WIGOS Subcomponents
  • Subcomponent 2
  • Multi-angle, multi-polarization radiometers
  • Multi-angle, multi-polarization radiometer
Mission objectives
Primary mission objectives
  • Aerosol Optical Depth
  • Aerosol column burden
  • Aerosol effective radius
  • Aerosol mass mixing ratio
  • Aerosol type
  • Aerosol volcanic ash
  • Aerosol volcanic ash Total Column
  • Cloud cover
  • Cloud optical depth
  • Cloud type
  • Earth surface albedo
  • Earth surface short-wave bidirectional reflectance
  • Short-wave cloud reflectance
  • Upward short-wave irradiance at TOA
Evaluation of Measurements

The following list indicates which measurements can typically be retrieved from this category of instrument. To see a full Gap Analysis by Variable, click on the respective variable.

Note: table can be sorted by clicking on the column headers
Note: * Primary mission objective.
VariableRelevance for measuring this variableOperational limitationsExplanation
Aerosol column burden*1 - primaryCloud sensitive.. Daylight only.VIS (with narrow bandwidth), NIR and SWIR channels including 760 nm, with multi-angle viewing and polarimetry for more aerosol types, also over land
Aerosol effective radius*1 - primaryCloud sensitive.. Daylight only.VIS (with narrow bandwidth), NIR and SWIR channels including 760 nm for high-level aerosol, with multi-angle viewing and polarimetry for several aerosol types, also over land
Aerosol mass mixing ratio*1 - primaryCloud sensitive.. Daylight only.VIS (with narrow bandwidth), NIR (including 760 nm for high-level aerosol) and SWIR channels, with multi-angle viewing and polarimetry for several aerosol types, also over land
Aerosol Optical Depth*1 - primaryCloud sensitive.. Daylight only.VIS (with narrow bandwidth), NIR and SWIR channels including 760 nm for high-level aerosol, with multi-angle viewing and polarimetry for more aerosol types, also over land
Aerosol type*1 - primaryCloud sensitive.. Daylight only.VIS (with narrow bandwidth), NIR and SWIR channels including 760 nm for high-level aerosol, with multi-angle viewing and polarimetry for more aerosol types, also over land
Biomass4 - fairCloud sensitive.. Index only.. Daylight only.VIS, NIR and SWIR channels. Biomass inferred from NDVI and LAI
Cloud cover*5 - marginalDaylight only.VIS and NIR channels
Cloud drop effective radius4 - fairAt cloud top.. Daylight only.VIS, NIR and SWIR channels and different viewing angles (for differentiation).
Cloud ice effective radius4 - fairAt cloud top.. Daylight only.VIS, NIR and SWIR channels with different viewing angles (for differentiation).
Cloud optical depth*2 - very highLow-density cloud only.. Daylight only.VIS, NIR and SWIR channels with different viewing angles
Cloud top height5 - marginalDaylight only.NIR channels to estimate the total-column O2 above the cloud top as measured around 760 nm
Cloud type*5 - marginalDaylight only.VIS, NIR and SWIR channels viewing under more angles
Colour Dissolved Organic Matter (CDOM)5 - marginalCloud sensitive.. Daylight only.A few narrow-bandwidth VIS channels, suitable for a few water types, mainly in open ocean
Downward short-wave irradiance at Earth surface3 - highCloud sensitive.. Highly indirect.VIS, NIR and SWIR channels
Earth surface albedo*1 - primaryCloud sensitive.VIS channels with many viewing angles to account for anisotropic reflectivity
Earth surface short-wave bidirectional reflectance*1 - primaryCloud sensitive.VIS, NIR and SWIR range with many different viewing angles
Fire fractional cover5 - marginalCloud sensitive.. Coarse spatial resolution.. Daylight only.VIS channels
Fraction of Absorbed PAR (FAPAR)1 - primaryCloud sensitive.VIS channels including Red at 700 nm, with more viewing angles
Leaf Area Index (LAI)2 - very highCloud sensitive.. Daylight only.VIS, NIR and SWIR channels
Normalised Difference Vegetation Index (NDVI)3 - highCloud sensitive.VIS and NIR channels
Ocean chlorophyll concentration 5 - marginalCloud sensitive.. Daylight only.A few narrow-bandwidth VIS channels, suitable for a few water types, mainly in open ocean
Ocean Diffuse Attenuation Coefficient (DAC)5 - marginalCloud sensitive.. Daylight only.A few narrow-bandwidth VIS channels, suitable for a few water types, mainly in open ocean
Ocean suspended sediments concentration5 - marginalCloud sensitive.. Daylight only.A few narrow-bandwidth VIS channels, suitable for a few water types, mainly in open ocean
Oil spill cover3 - highCloud sensitive.. Daylight only.VIS channels with narrow bandwidth, with different viewing angles
Photosynthetically Active Radiation (PAR)1 - primaryCloud sensitive.VIS channels, range undersampled; multi-viewing capability for irradiance reconstruction
Sea-ice cover4 - fairCloud sensitive.. Daylight only.VIS, NIR (for contour enhancement) and SWIR (for discrimination from clouds) channels
Short-wave cloud reflectance*1 - primaryNo specific limitation.VIS, NIR and SWIR channels with multi-viewing and multi-polarisation capabiliy to account for anisotropical reflectance
Snow cover2 - very highCloud sensitive.. Daylight only.VIS, NIR and SWIR channels, enabling screening snow from clouds
Soil moisture at surface5 - marginalCloud sensitive.. Index only.. Daylight only.VIS, NIR and SWIR channels. Soil moisture inferred from differential brightness
Integrated Water Vapour (IWV)4 - fairCloud sensitive.. Daylight only.NIR channels in the bands of water vapour around 900 nm and 940 nm
Upward short-wave irradiance at TOA*4 - fairSpectral interpolation needed.VIS, NIR and SWIR channels with multi-viewing and multi-polarisation capability to account for anisotropical reflectance
Aerosol volcanic ash*1 - primaryCloud sensitive.. Daylight only.VIS, NIR and SWIR channels including 760 nm, with multi-angle viewing and polarimetry for accurate ash identification, also over land
Aerosol volcanic ash Total Column*1 - primaryCloud sensitive.. Daylight only.VIS, NIR and SWIR channels including 760 nm, with multi-angle viewing and polarimetry for accurate ash identification, also over land