Aqua (2002-now)

NASA, Sun-synchronous, near polar orbit, afternoon (1:30 pm) ascending node, altitude 705 km

The NASA EOS-Aqua platform (Source:

The NASA EOS-Aqua (“water” in Latin) is a science satellite mission collecting information about the Earth’s water cycle, including evaporation from the oceans, water vapor in the atmosphere, clouds, precipitation, soil moisture, sea ice, land ice, and snow cover on the land and ice. Additional variables also being measured by Aqua include radiative energy fluxes, aerosols, vegetation cover on the land, phytoplankton and dissolved organic matter in the oceans, and air, land, and water temperatures. Aqua was originally developed for a six-year design life but has now far exceeded that original goal. It continues transmitting high-quality data from four of its six instruments:

  • Atmospheric InfraRed Sounder (AIRS)
  • Advanced Microwave Sounding Unit (AMSU-A)
  • Humidity Sounder for Brazil (HSB)
  • Advanced Microwave Scanning Radiometer for EOS (AMSR-E)
  • Moderate-Resolution Imaging Spectroradiometer (MODIS): passive sensor, atmosphere (aerosols, clouds, CO – Carbon monoxide), surface, fire
  • Clouds and the Earth’s Radiant Energy System (CERES)

Aura, NASA (2004-now)

The NASA EOS-Aura (“breeze” in Latin) satellite is focussed on observing atmospheric chemistry, in order to contribute to address major environmental questions related to the O3 – Ozone layer, the sources – chemical transformation and transport of tropospheric pollutants and the Earth’s climate. It consist of 4 instruments:

  • High Resolution Dynamics Limb Sounder (HIRDLS)
  • Microwave Limb Sounder (MLS)
  • Tropospheric Emission Spectrometer (TES)
  • Ozone Monitoring Instrument (OMI): Dutch-Finnish passive sensor, air quality purpose, designed for trace gas pollutants and aerosols

CALIPSO (2006-now)

Joint NASA and CNES

The Delta II rocket with CALIPSO and CloudSat (Source:
  • Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP): active sensor (lidar), high-resolution vertical profiles of aerosols and clouds.
  • Imaging Infrared Radiometer (IIR): cirrus cloud emissivity and particle size.
  • Wide Field Camera (WFC): a modified version of the commercial off-the-shelf Ball Aerospace CT-633 star tracker camera.

GOSAT (2009-)


MetOp A (2006-now), B (2012-now) & C (expected 2018)

EUMETSAT, low Earth Sun-Synchronous orbit, morning measurements

MetOp (Source:
  • Advanced Data collection System-2 (A-DCS): UHF receiver (401.65 MHz) and signal processor for locating and/or collecting meteorological data from remote fixed and free floating terrestrial and atmospheric platforms
  • Advanced Microwave Sounding unit A1 & A2 (AMSU-A): microwave sounder temperature clear & overcast conditions,
  • Advanced Very High Resolution Radiometer (AVHRR): passive imaging radiometer, cloud cover, sea surface temperature, ice, snow and vegetation cover
  • Advanced SCATterometer (ASCAT): pulsed radar C-band, global sea surface wind
  • Global navigation satellite system Receiver for Atmospheric Sounding (GRAS): Radio occultation, atmospheric temperature and humidity
  • Global Ozone Monitoring Experiment-2 (GOME-2): passive sensor, air quality purpose, trace gases (pollutants) & aerosols
  • High resolution Infrared Radiation Sounder (HIRS): atmospheric sounder, temperature, humidity, surface temperature, cloud & O3 – Ozone
  • InfraRed Atmospheric Sounding Interferometer (IASI): passive sensor, meteorology purpose (temperature, H2O – Water vapour), chemistry interest (trace gases)
  • Microwave Humidity Sounder (MHS): microwave radiometer, atmospheric H2O – water vapour
  • Search And Rescue SATellite (SARSAT) aided tracking system: VHF/UHF transponder and signal processor for locating and collecting information from remote distress platforms such as Emergency Locator Transmitters (ELTs), and Emergency Position Indicating Radio Beacons (EPIRBs)
  • Space Environment Monitor (SEM): VHF/UHF transponder and signal processor for locating and collecting information from remote distress platforms such as Emergency Locator Transmitters (ELTs), and Emergency Position Indicating Radio Beacons (EPIRBs)

Terra (1999-now)


Sentinel-5 Precursor (2017-now)

Supported by ESA and issued from initiatives by the Netherlands, Sentinel-5 Precursor is part of the COPERNICUS programme and the first of the atmospheric composition Sentinels, launched in 2017 for an expected lifetime of seven years.. Low Earth Sun-Synchronous orbit, altitude 824 km, local observation time 1:30 pm, it includes only 1 instrument: