BackForwardInstrument:  EPIC (DSCOVR) 

Instrument details
Acronym EPIC (DSCOVR)
Full name Earth Polychromatic Imaging Camera
Purpose Continuous viewing of the sun-illuminated Earth's disk in the UV, VIS and NIR bands
Short description CCD, 2048 x 2048 detectors, 10-channel UV/VIS/NIR radiometer [see details in the table below]
Background DSCOVR is the refurbishment of the Triana satellite stored on the ground in 2000 [named after Rodrigo de Triana, the first of Columbus' crew to catch sight of land in the Americas]
Scanning Technique Continuous Earth disc pointing from the L1 Lagrange libration point. East-West scanning provided by the Earth's rotation
Resolution 8 km s.s.p.
Coverage / Cycle Earth disk viewing the Sun each 20 s
Mass 63.2 kg Power 62 W Data Rate

 

Providing Agency NASA
Instrument Maturity Demonstration pending
Utilization Period: 2015-10-28 to ≥2020
Last update: 2017-03-27
Detailed characteristics

Central wavelength

Bandwidth

SNR @ specified input spectral radiance

317 nm

1 nm

….@....W m-2 sr-1 μm-1

325 nm

1 nm

….@....W m-2 sr-1 μm-1

340 nm

3 nm

….@....W m-2 sr-1 μm-1

388 nm

3 nm

….@....W m-2 sr-1 μm-1

443 nm

3 nm

….@....W m-2 sr-1 μm-1

552 nm

3 nm

….@....W m-2 sr-1 μm-1

680 nm

2 nm

….@....W m-2 sr-1 μm-1

688 nm

0.8 nm

….@....W m-2 sr-1 μm-1

764 nm

1 nm

….@....W m-2 sr-1 μm-1

779 nm

2 nm

….@....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
Mission objectives
Primary mission objectives
  • Aerosol Optical Depth
  • Aerosol column burden
  • Aerosol volcanic ash Total Column
  • Cloud cover
  • Cloud optical depth
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Tentative 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
VariableRelevance for measuring this variableOperational limitationsExplanation
Aerosol column burden3 - highCloud sensitive.. Daylight only.VIS (with narrow bandwidth) and NIR channels including 760 nm for high-level aerosol
Aerosol effective radius3 - highCloud sensitive.. Daylight only.VIS (with narrow bandwidth) and NIR channels including 760 nm for high-level aerosol
Aerosol mass mixing ratio3 - highCloud sensitive.. Daylight only.VIS (with narrow bandwidth) and NIR channels including 760 nm for high-level aerosol
Aerosol Optical Depth3 - highCloud sensitive.. Daylight only.VIS (with narrow bandwidth) and NIR channels including 760 nm for high-level aerosol
Aerosol type3 - highCloud sensitive.. Daylight only.VIS (with narrow bandwidth) and NIR channels including 760 nm for high-level aerosol
Biomass5 - marginalCloud sensitive.. Index only.. Daylight only.VIS and NIR channels. Biomass inferred from NDVI
Cloud cover5 - marginalDaylight only.VIS and NIR channels
Cloud optical depth4 - fairLow-density cloud only.. Daylight only.VIS and NIR channels
Cloud top height5 - marginalDaylight only.NIR channels to estimate the total-column O2 above the cloud top as measured around 760 nm
Cloud type5 - marginalDaylight only.VIS and NIR channels
Colour Dissolved Organic Matter (CDOM)3 - highCloud sensitive.. Daylight only.A few VIS channels, including broad, narrow, and very narrow ones. Suitable for a few water types, mainly in open ocean
Downward short-wave irradiance at Earth surface5 - marginalCloud sensitive.. Highly indirect.VIS and NIR channels
Earth surface albedo3 - highCloud sensitive.VIS channel with changing solar incidence angles as daylight progresses
Fire fractional cover5 - marginalCloud sensitive.. Coarse spatial resolution.. Daylight only.VIS channels
Fraction of Absorbed PAR (FAPAR)4 - fairCloud sensitive.VIS channels including Red at 700 nm
Leaf Area Index (LAI)4 - fairCloud sensitive.. Daylight only.VIS and NIR channels. LAI inferred from NDVI
Normalised Difference Vegetation Index (NDVI)3 - highCloud sensitive.VIS and NIR channels
O3 Total Column4 - fairCloud sensitive.. Daylight only.UV channels. Ozone line in the band around 340 nm (Huggins)
Ocean chlorophyll concentration 3 - highCloud sensitive.. Daylight only.A few VIS channels, including narrow, and very narrow ones. Suitable for a few water types, mainly in open ocean
Ocean Diffuse Attenuation Coefficient (DAC)3 - highCloud sensitive.. Daylight only.A few VIS channels, including narrow, and very narrow ones. Suitable for a few water types, mainly in open ocean
Ocean suspended sediments concentration3 - highCloud sensitive.. Daylight only.A few VIS channels, including narrow, and very narrow ones. Suitable for a few water types, mainly in open ocean
Oil spill cover5 - marginalCloud sensitive.. Daylight only.VIS channels with narrow bandwidth
Photosynthetically Active Radiation (PAR)4 - fairCloud sensitive.VIS channels, range undersampled
Sea-ice cover5 - marginalCloud sensitive.. Daylight only.VIS and NIR (for contour enhancement) channels
Short-wave cloud reflectance5 - marginalNo specific limitation.VIS and NIR channels
Snow cover4 - fairCloud sensitive.. Daylight only.VIS and NIR channels
Soil moisture at surface5 - marginalCloud sensitive.. Index only.. Daylight only.VIS and NIR channels. Soil moisture inferred from differential brightness
Upward short-wave irradiance at TOA4 - fairSpectral interpolation needed.. Information on BRDF needed.UV, VIS and NIR channels
Aerosol volcanic ash3 - highCloud sensitive.. Daylight only.VIS and NIR channels including 760 nm for high-level ashes
Aerosol volcanic ash Total Column2 - very highCloud sensitive.. Daylight only.UV (specifically sensitive to ash), VIS and NIR channels