BackForwardInstrument:  S-VISSR (FY-2C/D/E) 

Instrument details
Acronym S-VISSR (FY-2C/D/E)
Full name Stretched Visible and Infrared Spin Scan Radiometer
Purpose Multi-purpose imagery and wind derivation by tracking clouds and water vapour features
Short description 5 VIS/MWIR/TIR channels [see detailed characteristics below]
Background Two channels added in respect of the FY-2 A/B version: one MWIR, and split TIR
Scanning Technique Mechanical, spinning satellite, E-W continuous, S-N stepping
Resolution 5.0 km for IR channels; 1.25 km for the VIS channel
Coverage / Cycle Full disk every 30 min. Limited areas in correspondingly shorter time intervals
Mass 82 kg Power 75 W Data Rate 14 Mbps

 

Providing Agency CMA
Instrument Maturity Flown on operational programme
Utilization Period: 2005 to 2018
Last update: 2022-07-25
Detailed characteristics

Spectral interval

SNR or NEΔT @ specified input

0.55 - 0.99 µm

43 @ 95 % albedo

3.50 - 4.00 µm

0.5 K @ 300 K

6.30 - 7.60 µm

1.0 K @ 300 K

10.3 - 11.3 µm

0.5 K @ 300 K

11.5 - 12.5 µm

0.5 K @ 300 K
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
  • Multi-spectral VIS/IR imagery With rapid repeat cycles [in GEO]
  • Multi-spectral VIS/IR imager with rapid repeat cycles [in GEO]
Mission objectives
Primary mission objectives
  • Cloud cover
  • Cloud top height
  • Cloud top temperature
  • Cloud type
  • Integrated Water Vapour (IWV)
  • Wind (horizontal)
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
Accumulated precipitation4 - fairConvective precipitation dominant.. Calibration by MW needed.TIR channel(s) in the 10-13 micrometers range. Frequent sampling (GEO) is essential for accumulated precipitation.
Cloud cover*3 - highNo specific limitation.VIS, MWIR and TIR channels
Cloud top height*3 - highNo specific limitation.TIR channels in window and water vapour band (for emissivity) to estimate cloud top height from its temperature
Cloud top temperature*2 - very highNo specific limitation.TIR channels in window and water vapour band (for emissivity)
Cloud type*3 - highNo specific limitation.VIS, MWIR and TIR channels
Downward long-wave irradiance at Earth surface4 - fairCloud sensitive.. Highly indirect.MWIR and TIR channels including the water vapour band
Fire fractional cover4 - fairCloud sensitive.. Coarse spatial resolution.VIS, MWIR and TIR channels. Frequent sampling (GEO) enables early detection
Fire radiative power2 - very highCloud sensitive.. Coarse spatial resolution.MWIR and TIR channels. Frequent sampling (GEO) enables early detection
Fire temperature2 - very highCloud sensitive.. Coarse spatial resolution.MWIR and TIR channels. Frequent sampling (GEO) enables early detection
Land surface temperature3 - highCloud sensitive.MWIR and TIR window channels (high sensitivity to high temperature, cloud impact reduction, water vapour correction)
Precipitation intensity at surface (liquid or solid)3 - highConvective precipitation dominant.. Calibration by MW needed.TIR channel(s) in the 11 micrometers window. Frequent sampling (GEO) consistent with precipitation temporal variability
Sea surface temperature2 - very highCloud sensitive.MWIR and TIR window channels around 3.7 and 11 micrometers (cloud impact reduction, water vapour correction)
Snow cover5 - marginalCloud sensitive.. Daylight only.VIS channel(s). Frequent sampling (GEO) improves probability of cloud-free views
Soil moisture at surface4 - fairCloud sensitive.. Index only.VIS, MWIR and TIR channels. Soil moisture inferred from thermal inertia, that is accurately measured by frequent sampling (GEO)
Integrated Water Vapour (IWV)*2 - very highCloud sensitive.TIR channels around 6.3 micrometers and in the 11 micrometers split window
Upward long-wave irradiance at TOA5 - marginalSpectral interpolation needed.MWIR and TIR channels in windows around 3.7 and 11 micrometers, and in the water vapour band around 6.3 micrometers
Upward long-wave irradiance at Earth surface4 - fairCloud sensitive.. Highly indirect.MWIR and TIR channels in windows around 3.7 and 11 micrometers, and in the water vapour band around 6.3 micrometers
Aerosol volcanic ash Total Column1 - primaryCloud sensitive.TIR channel(s). Frequent sampling (GEO) enables early detection of ash plumes
Wind (horizontal)*3 - highCloud or water vapour tracers needed.VIS channel(s) and TIR channels around 6.3 and 11 micrometers. Frequent sampling (GEO) enables inference from cloud or water vapour pathces motion