BackForwardInstrument:  VHRI-100 

Instrument details
Acronym VHRI-100
Full name Very High Resolution Imager - 100
Purpose High resolution land observation and disaster monitoring
Short description Also named "SSTL-300 S1 Imager" - 5-channel VIS/NIR radiometer including one panchromatic. See details in the table below
Background Upgraded radiometer for the new generation of satellites contributing to the Disaster Monitoring Constellation
Scanning Technique Pushbroom, 23-km swath addressable within a Fied-of-Regard of 1200 km. Along-track stereo capablty by satellite tilting
Resolution 1 m for PAN, 4 m for multispectral, at the s.s.p.
Coverage / Cycle Global, at rate depending on the pointing strategy
Mass Power Data Rate

 

Providing Agency CAST
Instrument Maturity Flown on operational programme
Utilization Period: 2015 to 2025
Last update: 2021-08-31
Detailed characteristics

Central wavelength

Spectral interval

SNR @ specified albedo

475 nm

440 - 510 nm

100 @ 10 % albedo

550 nm

510 - 590 nm

100 @ 10 % albedo

635 nm

600 - 670 nm

100 @ 10 % albedo

835 nm

760 - 910 nm

100 @ 10 % albedo

PAN

450 - 650 nm

100 @ 10 % 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 1
  • High-resolution multi-spectral VIS/IR imagers
  • High-resolution multi-spectral VIS/IR imager
  • Subcomponent 4
  • GNSS radio occultation (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 topography4 - fairCloud sensitive.. Long time for mapping.. Daylight only.VIS and panchromatic channels with cross- and along-track steering capability for stereoscopy both in-orbit and between orbits
Ice sheet topography4 - fairCloud sensitive.. Long time for mapping.. Daylight only.VIS and panchromatic channels with cross- and along-track steering capability for stereoscopy both in-orbit and between orbits
Land cover*2 - very highCloud sensitive.. Daylight only.VIS and NIR channels
Land surface topography4 - fairCloud sensitive.. Long time for mapping.. Daylight only.VIS and panchromatic channels with cross- and along-track steering capability for stereoscopy both in-orbit and between 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