BackForwardInstrument:  GIS 

Instrument details
Acronym GIS
Full name GeoEye Imaging System
Purpose Very-high-resolution land imagery
Short description 5-channel VIS/NIR radiometer with one panchromatic channel and 4 multi-spectral. 110-cm telescope [see detailed characteristics below]
Background Evolution of OSA on Ikonos and OHRIS on OrbView-3
Scanning Technique Pushbroom, 35,000 detector array (PAN), 9,300 detector array (multispectral). Swath 15.2 km addressable by tilting the satellite in a variety of operating modes, within a Field-of-Regard of 620 km. Along-track stereo capability
Resolution 0.41 m (panchromatic), 1.64 m (multi-spectral)
Coverage / Cycle Global coverage in 6 months, in daylight; in few days (down to 4) by strategic pointing
Mass 452 kg Power Data Rate

 

Providing Agency GeoEye
Instrument Maturity Flown on operational programme
Utilization Period: 2009 to 2025
Last update: 2022-08-08
Detailed characteristics
Central wavelength Spectral interval SNR @ specified albedo
N/A (PAN) 450 - 900 nm ……….. @ ……… % albedo
485 nm 450 - 520 nm ……….. @ ……… % albedo
560 nm 520 - 600 nm ……….. @ ……… % albedo
660 nm 625 - 695 nm ……….. @ ……… % albedo
830 nm 760 - 900 nm ……….. @ ……… % albedo
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
  • High resolution optical imager
WIGOS Subcomponents
  • Subcomponent 4
  • High-resolution optical observation constellation (commercial)
  • High-resolution optical observation constellation (commercial)
Mission objectives
Primary mission objectives
  • Biomass
  • Fraction of Absorbed PAR (FAPAR)
  • Fraction of vegetated land
  • Land cover
  • Leaf Area Index (LAI)
  • Normalised Difference Vegetation Index (NDVI)
  • Vegetation type
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
Biomass*5 - marginalCloud sensitive.. Index only.. Infrequent coverage.. Daylight only.VIS and NIR channels. Biomass inferred from NDVI
Cloud cover5 - marginalInfrequent coverage.. Daylight only.VIS and NIR channels
Cloud optical depth4 - fairLow-density cloud only.. Infrequent coverage.. Daylight only.VIS and NIR channels
Earth surface albedo5 - marginalCloud sensitive.. Infrequent coverage.VIS channels
Fire fractional cover2 - very highCloud sensitive.. Daylight only.VIS channels with high resolution for boundary detection
Fraction of Absorbed PAR (FAPAR)*4 - fairCloud sensitive.. Infrequent coverage.VIS channels including Red at 700 nm
Fraction of vegetated land*2 - very highCloud sensitive.. Daylight only.VIS and NIR channels
Glacier cover4 - fairCloud sensitive.. Long time for mapping.. Daylight only.VIS and NIR channels; and panchromatic channel with high resolution, for glacier boundary detection
Glacier topography5 - marginalCloud sensitive.. Long time for mapping.. Daylight only.VIS and panchromatic channels with cross-track steering capability for stereoscopy between images from neighbour orbits
Ice sheet topography5 - marginalCloud sensitive.. Long time for mapping.. Daylight only.VIS and panchromatic channels with cross-track steering capability for stereoscopy between images from neighbouring orbits
Land cover*2 - very highCloud sensitive.. Daylight only.VIS and NIR channels
Land surface topography5 - marginalCloud sensitive.. Long time for mapping.. Daylight only.VIS and panchromatic channels with cross-track steering capability for stereoscopy between images from neighbour orbits
Leaf Area Index (LAI)*4 - fairCloud sensitive.. Daylight only.. Infrequent coverage.VIS and NIR channels. LAI inferred from NDVI
Normalised Difference Vegetation Index (NDVI)*2 - very highCloud sensitive.. Infrequent coverage.VIS and NIR channels
Photosynthetically Active Radiation (PAR)4 - fairCloud sensitive.. Infrequent coverage.VIS channels, range undersampled
Short-wave cloud reflectance5 - marginalInfrequent coverage.VIS and NIR channels. Unsuitable dynamic range (saturation)
Snow cover4 - fairCloud sensitive.. Infrequent coverage.. Daylight only.VIS, NIR and panchromatic (higher resolution) channels
Soil moisture at surface5 - marginalCloud sensitive.. Index only.. Infrequent coverage.. Daylight only.VIS and NIR channels. Soil moisture inferred from differential brightness
Soil type2 - very highCloud sensitive.. Daylight only.VIS and NIR channels
Upward short-wave irradiance at TOA5 - marginalSpectral interpolation needed.. Information on BRDF needed.. Infrequent coverage.VIS and NIR channels
Vegetation type*3 - highCloud sensitive.. Daylight only.VIS and NIR channels
Aerosol volcanic ash5 - marginalCloud sensitive.. Infrequent coverage.. Daylight only.VIS and NIR channels
Aerosol volcanic ash Total Column5 - marginalCloud sensitive.. Infrequent coverage.. Daylight only.VIS and NIR channels
Sea-ice cover5 - marginalCloud sensitive.. Daylight only.VIS and NIR (for contour enhancement) channels