BackForwardInstrument:  OCI 

Instrument details
Acronym OCI
Full name Ocean Color Instrument
Purpose To measure ccean colour, vegetation, aerosol, and cloud properties
Short description

Hyperspectral radiometry from the ultraviolet (340 nm) to SWIR (2260 nm). Bandwidth at 5 nm resolution and spectral steps of 2.5 nm (with spectral steps of 1.25 nm in a limited number of wavelength ranges) up to 888 nm. Shortwave (SW) infrared (IR) bands include: 940, 1038, 1250, 1378, 1615, 2130, and 2260 nm. Spectral response tables can be found here

Daily and monthly solar calibrations using two onboard solar diffusers. Bi-monthly lunar calibrations. Monthly linearity measurements with a dim solar diffuser.
Background

New development based on CZCS and SeaWIFS instruments
Scanning Technique

Scanning mirror. Off-nadir view to avoid sun glint.  Along track tilt 19.9°, aft in the southern hemisphere, fore in the northern hemisphere. −56.0° to +56.5°, swath width of ~2700 km.
Resolution 1.2 km
Coverage / Cycle 2-day global coverage at 1.2 km
Mass 272 kg Power 237 W Data Rate

 

Providing Agency NASA
Instrument Maturity Backed by strong heritage
Utilization Period: 2024 to 2027
Last update: 2024-02-19
Detailed characteristics
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 1
  • Narrow-band or hyperspectral imagers
  • Narrow-band imager (for ocean colour)
Mission objectives
Primary mission objectives
  • Aerosol Optical Depth
  • Aerosol column burden
  • Cloud cover
  • Cloud optical depth
  • Cloud type
  • Colour Dissolved Organic Matter (CDOM)
  • Fraction of Absorbed PAR (FAPAR)
  • Leaf Area Index (LAI)
  • Normalised Difference Vegetation Index (NDVI)
  • Ocean Diffuse Attenuation Coefficient (DAC)
  • Ocean chlorophyll concentration
  • Ocean suspended sediments concentration
  • Oil spill cover
  • Photosynthetically Active Radiation (PAR)
  • Sea-ice cover
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*3 - highCloud sensitive.. Daylight only.UV (for absorbing aerosol), VIS (with narrow bandwidth), NIR and SWIR channels including 760 nm for high-level aerosol
Aerosol effective radius3 - highCloud sensitive.. Daylight only.UV (for absorbing aerosol), VIS (with narrow bandwidth), NIR and SWIR channels including 760 nm for high-level aerosol
Aerosol mass mixing ratio3 - highCloud sensitive.. Daylight only.UV (for absorbing aerosol), VIS (with narrow bandwidth), NIR (including 760 nm for high-level aerosol) and SWIR channels
Aerosol Optical Depth*3 - highCloud sensitive.. Daylight only.UV (for absorbing aerosol),VIS (with narrow bandwidth), NIR and SWIR channels including 760 nm for high-level aerosol
Aerosol type3 - highCloud sensitive.. Daylight only.UV (for absorbing aerosol), VIS (with narrow bandwidth), NIR and SWIR channels including 760 nm for high-level aerosol
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 optical depth*3 - highLow-density cloud only.. Daylight only.VIS, NIR and SWIR channels
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 and NIR channels
Colour Dissolved Organic Matter (CDOM)*1 - primaryCloud sensitive.. Daylight only.Many narrow-bandwidth VIS channels, suitable for more water types, in open ocean and coastal zone
Downward short-wave irradiance at Earth surface3 - highCloud sensitive.. Highly indirect.VIS, NIR and SWIR channels
Earth surface albedo5 - marginalCloud sensitive.VIS channels
Fire fractional cover5 - marginalCloud sensitive.. Coarse spatial resolution.. Daylight only.VIS channels
Fraction of Absorbed PAR (FAPAR)*3 - highCloud sensitive.VIS channels including Red at 700 nm
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 *1 - primaryCloud sensitive.. Daylight only.Many narrow-bandwidth VIS channels, suitable for more water types, in open ocean and coastal zone
Ocean Diffuse Attenuation Coefficient (DAC)*1 - primaryCloud sensitive.. Daylight only.Many narrow-bandwidth VIS channels, suitable for more water types, in open ocean and coastal zone
Ocean suspended sediments concentration*1 - primaryCloud sensitive.. Daylight only.Many narrow-bandwidth VIS channels, suitable for more water types, in open ocean and coastal zone
Oil spill cover*5 - marginalCloud sensitive.. Daylight only.VIS channels with narrow bandwidth
Photosynthetically Active Radiation (PAR)*3 - highCloud sensitive.VIS channels, range accurately sampled
Sea-ice cover*4 - fairCloud sensitive.. Daylight only.VIS, NIR (for contour enhancement) and SWIR (for discrimination from clouds) channels
Short-wave cloud reflectance4 - fairNo specific limitation.VIS, NIR and SWIR channels
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
Upward short-wave irradiance at TOA4 - fairSpectral interpolation needed.. Information on BRDF needed.UV, VIS, NIR and SWIR channels
Aerosol volcanic ash3 - highCloud sensitive.. Daylight only.UV, VIS, NIR and SWIR channels, including 760 nm for high-level ashes
Aerosol volcanic ash Total Column3 - highCloud sensitive.. Daylight only.UV (specifically sensitive to ash), VIS, NIR and SWIR channels, including 760 nm for high-level ashes