THE CEOS DATABASE : Missions, Instruments and Measurements
CEOS EO HANDBOOK – MEASUREMENT INSTRUMENTS
Measurements > Atmosphere >
Atmospheric Humidity Fields >
Atmospheric specific humidity (column/profile)


Measurement Definition*: Vertical profile of the specific humidity in the atmosphere - Requested from surface to TOA (layers: LT, HT, LS, HS&M) + Total column - Physical units: [ g/kg ] for profile, [ kg/m2 ] for total column - Accuracy unit: [ % ] for profile, [ kg/m2 ] for total column.
InstrumentStatus/
Accuracy
Instrument DescriptionMeasurement TechnologyTimeline
Advanced MI
Advanced Meteorological Imager
Operational
Continuous monitoring capability for the near real-time generation of high-resolution meteorological products and long-term change analysis of sea surface temperature and cloud coverage.n/a
AIRS
Atmospheric Infra-red Sounder
Operational
High spectral resolution measurement of temperature and humidity profiles in the atmosphere. Long-wave Earth surface emissivity. Cloud diagnostics. Trace gas profiles. Surface temperatures.n/a
AltiKa
Ka-band Altimeter
Operational
Sea surface height.n/a
AMR
Advanced Microwave Radiometer
Operational
Altimeter data to correct for errors caused by water vapour and cloud-cover. Also measures total water vapour and brightness temperature.n/a
AMSR-2
Advanced Microwave Scanning Radiometer -2
Operational
+/-1.5 kg/m2
Measurements of water vapour, cloud liquid water, precipitation, winds, sea surface temperature, sea ice concentration, snow cover, soil moisture.n/a
AMSU-A
Advanced Microwave Sounding Unit-A
Operational
All-weather night-day temperature sounding to an altitude of 45 km.n/a
AMSU-A
Advanced Microwave Sounding Unit-A
Operational
All-weather night-day temperature sounding to an altitude of 45 km. AMSU-A on Aqua is still partially operational, with 9 of the 15 channels working and collecting data.n/a
ASI
Atmospheric Sounding Interferometer
Operational
Atmospheric sounding for weather forecasting.n/a
ATMS
Advanced Technology Microwave Sounder
Operational
Collects microwave radiance data that when combined with the CrIS data will permit calculation of atmospheric temperature and water vapour profiles.n/a
CrIS
Cross-track Infrared Sounder
Operational
Daily measurements of vertical atmospheric distribution of temperature, moisture, and pressure.n/a
GIIRS
Geostationary Interferometric Infrared Sounder
Operational
Measurements of three dimensional atmospheric structure. Large-area, continuous, fast, and accurate vertical air soundings of temperature and humidity. Subsequent units have slightly different specifications.n/a
GMI
GPM Microwave Imager
Operational
Measures rainfall rates over oceans and land, combined rainfall structure and surface rainfall rates with associated latent heating. Used to produce three hour, daily, and monthly total rainfall maps over oceans and land.n/a
GNOS
GNSS Radio Occultation Sounder
Operational
Atmospheric sounding for weather forecasting.n/a
GOME-2
Global Ozone Monitoring Experiment - 2
Operational
Measurement of total column amounts and stratospheric and tropospheric profiles of ozone. Also amounts of H20, NO2, OClO, BrO, SO2 and HCHO.n/a
GOX
Global Positioning Satellite Occultation Experiment (GOX)
Operational
Each instrument equipped with 4 GPS antennas to receive the L1 and L2 radio wave signals transmitted from the 24 US GPS satellites. Based on the signal transmission delay caused by the electric density, temperature, pressure, and water content in the ionon/a
GPSRO (Oersted)
GPS Radio Occultation System
Operational
Measurements of atmospheric temperature, pressure and water vapour content.n/a
GPSRO (Terra-SAR)
GPS Radio Occultation System
Operational
Measurements of atmospheric temperature, pressure and water vapour content.n/a
GRAS
GNSS Receiver for Atmospheric Sounding
Operational
GNSS receiver for atmospheric temperature and humidity profile sounding.n/a
HIRAS
Hyperspectral Infrared Atmospheric Sounder
Operational
 n/a
IASI
Infrared Atmospheric Sounding Interferometer
Operational
Measures tropospheric moisture and temperature, column integrated contents of ozone, carbon monoxide, methane, nitrous oxide and other minor gases which affect tropospheric chemistry. Also measures sea surface and land temperature.n/a
IKFS-2
IR-Fourier spectrometer
Operational
Atmospheric temperature/humidity profiles, data on cloud parameters, water vapour & ozone column amounts, surface temperature.n/a
MAESTRO
Measurements of Aerosol Extinction in the Stratosphere and Troposphere Retrieved by Occultation
Operational
Chemical processes involved in the depletion of the ozone layer, and now including a high quality water vapour data product.n/a
MHS
Microwave Humidity Sounder
Operational
Atmospheric humidity profiles, cloud cover, cloud liquid, water content, ice boundaries and precipitation data.n/a
MI
Meteorological Imager
Operational
Continuous monitoring capability for the near real-time generation of high-resolution meteorological products and long-term change analysis of sea surface temperature and cloud coverage.n/a
MLS (EOS-Aura)
Microwave Limb Sounder (EOS-Aura)
Operational
Measures lower stratospheric temperature and concentration of H2O, O3, ClO, HCl, OH, HNO3, N2O and SO2.n/a
MODIS
MODerate-Resolution Imaging Spectroradiometer
Operational
Data on biological and physical processes on the surface of the Earth and in the lower atmosphere, and on global dynamics. Surface temperatures of land and ocean, chlorophyll fluorescence, land cover measurements, cloud cover (day and night).n/a
MSU-GS
Multispectral scanning imager-radiometer
Operational
Measurements of cloud cover, cloud top height, precipitation, cloud motion, albedo, vegetation, convection, air mass analysis, tropopause monitoring, stability monitoring, total ozone and surface temperature, fire detection.n/a
MTVZA-GY
Scanning microwave imager-sounder
Operational
Atmospheric temperature and humidity profiles, precipitation, sea-level wind speed, snow/ice coverage.n/a
MWHS-1
Micro-Wave Humidity Sounder
Operational
Meteorological applications.n/a
MWHS-2
Improved MicroWave Humidity Sounder
Operational
Meteorological applications.n/a
MWRI
Micro-Wave Radiation Imager
Operational
All weather observations of precipitation, cloud features, vegetation, soil moisture sea ice, etc.n/a
MWTS-2
Micro-Wave Temperature Sounder-2
Operational
Atmospheric sounding measurements.n/a
RAD
Microwave radiometer
Operational
Ocean wind and temperature measurements.n/a
SAGE-III
Stratospheric Aerosol and Gas Experiment
Operational
Limb-viewing measurements of aerosol, O3, H20, NO2, OClO, NO3, temperature and pressure in the stratosphere, upper troposphere, and mesosphere using solar occultation, lunar occultation and limb scatter measurement techniques.n/a
SAPHIR
Sondeur Atmospherique du Profil'd’Humidite Intertropicale par Radiometrie
Operational
Cross-track sounder with the objective of measuring water vapour profiles in the troposphere in six layers from 2 - 12 km altitudes.n/a
SEVIRI
Spinning Enhanced Visible and Infra-Red Imager
Operational
Measurements of cloud cover, cloud top height, precipitation, cloud motion, vegetation, radiation fluxes, convection, air mass analysis, cirrus cloud discrimination, tropopause monitoring, stability monitoring, total ozone and sea surface temperature.n/a
SMR
Submillimetre Radiometer
Operational
Measures global distributions of ozone and species of importance for ozone chemistry ClO, HNO3, H2O, N2O, (HO2, H2O2). Measures temperature in the height range 15 - 100 km.n/a
Sounder
Sounder
Operational
Atmospheric soundings and data on atmospheric stability and thermal gradient winds.n/a
Sounder (INSAT)
IR Sounder
Operational
Atmospheric soundings, atmospheric stability, thermal gradient winds.n/a
SRAL
SAR Radar Altimeter
Operational
Marine and land services.n/a
SSM/I
Special Sensor Microwave Imager
Operational
Measures atmospheric, ocean and terrain microwave brightness temperatures to provide: sea surface winds, rain rates, cloud water, precipitation, soil moisture, ice edge, ice age.n/a
SSM/IS
Special Sensor Microwave Imager Sounder
Operational
Measures thermal microwave radiation. Global measurements of air temp profile, humidity profile, ocean surface winds, rain overland/ocean, ice concentration/age, ice/snow edge, water vapour/clouds over ocean, snow water content, land surface temperature.n/a
SSM/T-2
Special Sensor Microwave Water Vapor Sounder
Operational
Water vapour profiler.n/a
UVNS (Sentinel-5 precursor)
TROPOMI
Operational
Supporting atmospheric composition and air quality monitoring services.n/a
AMR-C
AMR-C Climate-quality microwave radiometer
Being developed
Capabilities of the AMR with the addition of high stability wet-tropospheric path delay correction.n/a
AMR-S
AMR-S Two-Beam Microwave Radiometer
Being developed
Capabilities of the AMR with the addition of a 2nd beam to provide wet-tropospheric path delay correction within both swaths of the primary radar instrument (KaRIn)n/a
FCI
Flexible Combined Imager
Being developed
Measurements of cloud cover, cloud top height, precipitation, cloud motion, vegetation, radiation fluxes, convection, air mass analysis, cirrus cloud discrimination, tropopause monitoring, stability monitoring, total ozone and sea surface temperature.n/a
GNSS-RO Receiver
GNSS Radio Occultation Receiver
Being developed
 n/a
IASI-NG
Infrared Atmospheric Sounding Interferometer - New Generation
Being developed
Measures profiles of atmospheric temperature, humidity, ozone, carbon monoxide, columns of methane, nitrous oxide, and other minor gases, and sea, ice, and land surface temperature and emissivity.n/a
ICI
Ice Cloud Imager
Being developed
Measures cloud ice content, snowfall detection, precipitation content, snowfall rate near surface and water vapour profilesn/a
IRS
Infra-Red Sounder
Being developed
Measurements of vertically resolved clear sky atmospheric motion vectors, temperature and water vapour profiles.n/a
MWI
Microwave Imager
Being developed
Measure cloud liquid water, ice cloud content, precipitation, total column water vapour, snow parameters, sea ice parametersn/a
MWS
Microwave Sounder
Being developed
All-weather night-day temperature soundingn/a
RO
RO
Being developed
GNSS receiver for atmospheric temperature and humidity profile sounding.n/a
TROPICS
Microwave Spectrometer (TROPICS)
Being developed
+/-0.25
Constellation to provide temperature/moisture sounding and cloud/precipitation imaging with rapid update.n/a
UVNS (Sentinel-5)
Ultra-violet Visible Near-infrared Shortwave-infrared spectrometer
Being developed
Supporting atmospheric composition and air quality monitoring services. Measurements of atmospheric trace gases, primarily O3, NO2, SO2, HCHO, CH4 and CO.n/a
MSU-GS/VE
Multispectral scanning imager-radiometer
Approved
Operational metrology, hydrology, climate monitoring and environmental monitoringn/a
MVIRS
Moderate Resolution Visible and Infrared Imaging Spectroradiometer
Approved
Measures surface temperature and cloud and ice cover. Used for snow and flood monitoring and surface temperature.n/a
UVN
UV-VIS-NIR Sounder
Approved
Measurements of atmospheric trace gases, mainly O3, NO2, SO2, H2CO. The product list is not yet approved, the accuracy summary column lists the breakthrough user requirements.n/a
Advanced Radiomet
Advanced Radio-occultation receiver
Proposed
Atmospheric temperature and humidity profiles with high vertical resolution.n/a
AMSR-3
Advanced Microwave Scanning Radiometer -3
Proposed
+/-1.5 kg/m2
Measurements of water vapour, cloud liquid water, precipitation, winds, sea surface temperature, sea ice concentration, snow cover, soil moisture. n/a
GeoSTAR
MW Array Spectrometer (PATH)
Proposed
High frequency, all-weather temperature and humidity soundings for weather forecasting and SST.n/a
IKFS-3
Advanced Fourier spectrometer
Proposed
Atmospheric temperature/humidity profiles, data on cloud parameters, water vapour & ozone column amounts, surface temperature.n/a
MATHS
Millimeter wave Atmosphere Temperature and Humidity Sounder
Proposed
Integrated water vapour, cloud liquid water and precipitation for temperature soundingn/a
Microwave limb sounder (GACM)
Microwave limb sounder (GACM)
Proposed
Limb-viewing measurements of O3, N2O, temperature, water vapour, CO, HNO3, ClO, and volcanic SO2 in the.n/a
MTVZA-GY-MP
Advanced Scanning microwave imager-sounder
Proposed
Atmospheric temperature and humidity profiles, precipitation, sea-level wind speed, snow/ice coverage.n/a
TGRS
TriG (Tri-GNSS) GNSS Radio-occultation System
Proposed
TGRS is the radio occultation receiver, which will receive signals from GPS, Galileo, and Glonass.n/a
AMSR-E
Advanced Microwave Scanning Radiometer-EOS
No longer operational
+/-3.5 kg/m2
Measurements of water vapour, cloud liquid water, precipitation, winds, sea surface temperature, sea ice concentration, snow cover and soil moisture. Instrument stopped functioning 4th October 2011.n/a
HiRDLS
High Resolution Dynamics Limb Sounder
No longer operational
Measures atmospheric temperature, concentrations of ozone, water vapour, methane, NOx, N2O, CFCs and other minor species, aerosol concentration, location of polar stratospheric clouds and cloud tops. Currently not collecting data on Aqua.n/a
HIRS/4
High Resolution Infra-red Sounder/4
No longer operational
Atmospheric temperature profiles and data on cloud parameters, humidity soundings, water vapour, total ozone content, and surface temperatures. Same as HIRS/3, with 10 km IFOV.n/a
HSB
Humidity Sounder for Brazil
No longer operational
Humidity soundings for climatological and atmospheric dynamics applications. The scan mirror motor failed on 5th February 2003.n/a
IRAS
InfraRed Atmospheric Sounder
No longer operational
Atmospheric sounding for weather forecasting.n/a
TES
Tropospheric Emission Spectrometer
No longer operational
3D profiles on a global scale of all infra-red active species from surface to lower stratosphere. Measures greenhouse gas concentrations, tropospheric ozone, acid rain precursors, gas exchange leading to stratospheric ozone depletion.n/a
* Description adapted from WMO.
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