BackForwardInstrument:  GHMI 

Instrument details
Acronym GHMI
Full name Geostationary HiMawari Imager
Purpose Multi-purpose imagery for nowcasting, NWP assimilation and environment monitoring. Wind derivation by tracking clouds and water vapour features.
Short description 18 channel radiometer in VIS, NIR, SWIR, MWIR and TIR part of spectrum [see detailed characteristics below].
Background Heritage replacing AHI imager on Himawari-8/9 based on the same concept as GeoXO Imager (GXI).
Scanning Technique Mechanical, 3-axis stabilised satellite, E-W continuous, S-N stepping.
Resolution All channels less than 2km with some channels less than 1km. See table below.
Coverage / Cycle Full disk every 10 mins; Over Japan 2500x2000 km every 2.5 mins; several target areas 1000x1000km over E. Asia every 2.5 mins, and 1000x500 km target every 0.5 mins.
Mass Power Data Rate

 

Providing Agency JMA
Instrument Maturity Flown on operational programme
Utilization Period: TBD
Last update: 2023-05-05
Detailed characteristics
Centre wavelength (µm) Bandwidth (µm) Spatial resolution (km)
0.46 - 0.48 <0.07 <1
0.54 - 0.56 <0.05 <1
0.63 - 0.65 <0.12 <0.5
0.85 - 0.87 <0.06 <1
1.375 - 1.385 <0.04 <2
1.60 - 1.62 <0.08 <2
2.24 - 2.27 <0.06 <2
3.75 - 3.95 <0.5 <1
5.10 - 5.20 <0.2 <1
6.05 - 6.45 <1.2 <2
6.90 - 7.00 <0.5 <2
7.27 - 7.43 <0.6 <2
8.44 - 8.76 <0.5 <2
9.55 - 9.70 <0.5 <2
10.3 - 10.5 <0.9 <2
11.1 - 11.3 <1.0 <2
12.25 - 12.55 <1.2 <2
13.2 - 13.4 <0.7 <2
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
  • Aerosol Optical Depth
  • Cloud cover
  • Cloud optical depth
  • Cloud top height
  • Cloud top temperature
  • Cloud type
  • Integrated Water Vapour (IWV)
  • Sea surface temperature
  • 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 precipitation (over 24 h)3 - highConvective precipitation dominant.. Calibration by MW needed.TIR channels in the 11 micrometers window, and SWIR and the MWIR 3.7 window channel for cloud microphysics. Frequent sampling (GEO) is essential for accumulated precipitation
Aerosol column burden4 - fairCloud sensitive.. Daylight only.VIS, NIR and SWIR channels with changing solar incidence angles as daylight progresses
Aerosol Optical Depth*4 - fairCloud sensitive.. Daylight only.VIS, NIR and SWIR channels with changing solar incidence angles as daylight progresses
Biomass4 - fairCloud sensitive.. Index only.. Daylight only.VIS, NIR and SWIR channels. Biomass inferred from NDVI and LAI
Cloud cover*1 - primaryNo specific limitation.VIS, NIR, SWIR, MWIR and TIR channels
Cloud drop effective radius3 - highAt cloud top.. Daylight only.VIS, NIR, SWIR and MWIR channels (for differentiation)
Cloud ice effective radius3 - highAt cloud top.. Daylight only.VIS, NIR, SWIR and MWIR channels (for differentiation)
Cloud optical depth*3 - highLow-density cloud only.. Daylight only.VIS, NIR and SWIR channels
Cloud top height*2 - very highNo specific limitation.TIR channels in window and water vapour band (for emissivity) for temperature; and in CO2 band for atmospheric column above cloud top
Cloud top temperature*2 - very highNo specific limitation.TIR channels in window and water vapour band (for emissivity)
Cloud type*1 - primaryNo specific limitation.VIS, NIR, SWIR, MWIR and TIR channels
Downward short-wave irradiance at Earth surface3 - highCloud sensitive.. Highly indirect.VIS, NIR and SWIR channels
Downward long-wave irradiance at Earth surface4 - fairCloud sensitive.. Highly indirect.MWIR and TIR channels including water vapour and CO2 bands
Earth surface albedo3 - highCloud sensitive.VIS channel with changing solar incidence angles as daylight progresses
Earth surface short-wave bidirectional reflectance3 - highCloud sensitive.VIS, NIR and SWIR channels with changing solar incidence angles as daylight progresses
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
Fraction of Absorbed PAR (FAPAR)4 - fairCloud sensitive.VIS channels including Red at 700 nm
Land surface temperature3 - highCloud sensitive.MWIR and TIR window channels (high sensitivity to high temperature, cloud impact reduction, water vapour correction)
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
O3 Total Column5 - marginalCloud sensitive.TIR channel(s). Ozone lines in band around 9.7 micrometers. Frequent sampling (GEO) enables monitoring diurnal variations
Photosynthetically Active Radiation (PAR)4 - fairCloud sensitive.VIS channels, range undersampled
Precipitation intensity at surface (liquid or solid)3 - highConvective precipitation dominant.. Calibration by MW needed.TIR channels in the 11 micrometers window, and SWIR and the MWIR 3.7 window channel for cloud microphysics. Frequent sampling (GEO) consistent with precipitation temporal variability
Sea surface temperature*2 - very highCloud sensitive.MWIR and TIR window channels around 3.7 and 11 micrometers (cloud impact reduction, water vapour correction)
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. Frequent sampling improves probability of cloud-free views
Soil moisture at surface4 - fairCloud sensitive.. Index only.VIS, NIR, SWIR, MWIR and TIR channels. Soil moisture inferred from differential brightness and thermal inertia, that are accurately measured by frequent sampling (GEO)
Specific humidity3 - highCloud sensitive.. Coarse vertical resolution.. Middle troposphere only.TIR channels in the water vapour band around 6.3 micrometers
Integrated Water Vapour (IWV)*2 - very highCloud sensitive.TIR channels around 6.3 micrometers and in the 11 micrometers split window
Upward short-wave irradiance at TOA3 - highSpectral interpolation needed.VIS, NIR and SWIR channels with changing solar incidence angles as daylight progresses
Upward long-wave irradiance at TOA4 - fairSpectral interpolation needed.MWIR and TIR channels in windows around 3.7 and 11 micrometers, and in water vapour and CO2 bands around 6.3 and 15 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 water vapour and CO2 bands around 6.3 and 15 micrometers
Aerosol volcanic ash4 - fairCloud sensitive.. Daylight only.VIS, NIR and SWIR channels with changing solar incidence angles as daylight progresses
Aerosol volcanic ash Total Column1 - primaryCloud sensitive.TIR channel(s). Frequent sampling (GEO) enables early detection of ash plumes
Wind (horizontal)*2 - very highCloud or water vapour tracers needed.VIS channel(s) and TIR channels around 6.3 and 11 micrometers, and 13.3 micrometers for more accurate height assignment. Frequent sampling (GEO) enables inference from cloud or water vapour pathces motion