List of mission types

Mission type Definition
Multi-purpose VIS/IR imagery from LEOThis type of mission designates medium-resolution multi-channel radiometers operating in the VIS and IR parts of the spectrum in Low Earth Orbit.  
Multi-purpose VIS/IR imagery from GEOThis type of mission designates medium-resolution multi-channel radiometers operating in the VIS and IR parts of the spectrum, in geostationary orbit.  
IR temperature/humidity sounding from LEOThis type of mission designates medium spectral resolution spectrometers or radiometers operating in the IR part of the spectrum, in Low Earth Orbit.  
IR temperature/humidity sounding from GEOThis type of mission designates medium spectral resolution spectrometers or radiometers operating in the IR part of the spectrum, in geostationary orbit.  
MW temperature/humidity sounding from LEOThis type of mission designates MW radiometers operating in O2 or H2O absorption bands fo IR sounding in nearly all-weather conditions, in Low Earth Orbit.  
MW temperature/humidity sounding from GEOThis type of mission designates sounding/imaging radiometers in geostationary orbit. They operate in the millimetre and submillimetre ranges of the spectrum, to allow the use of antennas of practical sizes.  
MW imageryThis type of mission designates MW radiometers operated in Low Earth Orbit for various purposes. Generally exploiting conical scanning (thus with constant zenith angle) in order to operate with several polarisations, or cross-track pushbroom scanning for some low-frequency sensors. 
Radio occultation soundingThis type of mission designates receivers of signals from navigation systems (GPS, GLONASS, Galileo, Beidou) embarked on LEO satellites, operating during the occultation phase. The radio-occultation measurements are used for atmospheric temperature and humidity sounding, and/or for ionospheric sounding. 
Earth radiation budget from LEOThis type of mission designates two measuring systems: - broad-band radiometry of the total upward radiation (longwave emission of the Earth's atmosphere to Space and short-wave reflected solar radiation) measured from Low Earth Orbit; provision of additional information from key narrow-band channels, and multi-directional viewing (to retrieve irradiance), are necessary; - Cavity radiometers to measure the incoming solar radiation.  
Earth radiation budget from GEOThis type of mission designates two measuring systems in geostationary or higher orbits : (i) broad-band radiometry of the total upward radiation (emission from the Earth's amosphere to Space and of short-wave reflected solar radiation); (ii) incoming solar radiation. In complement to the Earth Radiation Budget monitoring from LEO, measurements acquired from several GEO satellites around the globe enable capturing diurnal variations. The L1 Lagrange libration point is also a privileged vantage point for solar monitoring  
Sea-surface wind by active and passive MWThis type of mission designates radar scatterometers that provide backscatter coefficient observations under a number of viewing angles. Another technique makes use of passive MW imagers exploiting several polarisations (up to full-polarisation) at different frequencies.  
Radar altimetryThis type of mission designates essentially nadir-pointing radars that measure the distance between the satellite and the reflecting sea surface. It can also be used on land and ice. It is possible to implement SAR capability to more accurately detect ice border and topography. To be associated with co-aligned passive MW radiometers for water vapour correction, and with precise orbit determination.  
Ocean colour imagery from LEOThis type of mission designates VIS/NIR imagers designed to work on low-level signals (because of low reflectivity of ocean) and narrow-bandwidth channels to address specific water features. Observation of aerosol is needed for atmospheric correction.  
Ocean colour imagery from GEOThis type of mission designates VIS/NIR imagers specifically designed to work on low-level signals (because of low reflectivity of ocean) and narrow bandwidth channels to address specific water features. Observation of aerosol is needed for atmospheric correction. Geostationary orbit.  
Imagery with special viewing geometryThis type of mission designates VIS/IR imagers viewing under different angles for specific purposes : accurate atmospheric correction, anisotropy effects, optimal geometry to exploit multi-polarisation, need for reconstructing irradiances from observed radiances, etc.  
Lightning imagery from GEO or LEOThis type of mission designates special cameras observing the Earth all-time and recording rate and intensity of flashes in a given area (the IFOV), from a Geostationary or Low Earth Orbit.  
Cloud and precipitation profiling by radarThis type of mission designates radars with different characteristics depending on the type of cloud to be observed: non-precipitating, with light-moderate precipitation, with heavy precipitation.  
Lidar observation (for wind, for cloud/aerosol, for trace gases, for altimetry)This type of mission designates lidars with different characteristics depending on the type of variable to be measured: wind, cloud, aerosol, water vapour, trace gases, altimetry.  
Cross-nadir SW spectrometry (for chemistry) from LEOThis type of mission designates short-wave spectrometers (UV/VIS/NIR/SWIR) designed for use in atmospheric chemistry, in LEO. 
Cross-nadir SW spectrometry (for chemistry) from GEOThis type of mission designates short-wave spectrometers (UV/VIS/NIR/SWIR) designed for use in atmospheric chemistry, in GEO.  
Cross-nadir IR spectrometry (for chemistry) from LEOThis type of mission designates IR spectrometers designed for use in atmospheric chemistry, in LEO. 
Cross-nadir IR spectrometry (for chemistry) from GEOThis type of mission designates IR spectrometers designed for use in atmospheric chemistry, GEO. 
Limb-sounding spectrometryThis type of mission designates limb-viewing spectrometers designed for use in atmospheric chemistry, in short waves (UV/VIS/NIR/SWIR), in IR or in millimeter/submillimeter waves.  
High-resolution imagery for land observationThis type of mission designates imagers, with various trade-offs between high spatial resolution and swath width, often steerable to enable in-flight selection of the area to be observed within the field of regard.  
Synthetic Aperture RadarThis type of mission designates side-looking radar associated to special signal analysis that enables very-high resolution imagery. The technology implies very precise trade-off between frequency, geometric resolution, swath and polarisation. 
Space Weather: solar activity monitoringThis type of mission designates solar imagery missions, to monitor sunspots, solar flares, coronal mass ejections and solar magnetic field, and measurement of the radiative fluxes emitted by the sun in different wavelengths (from Gamma-ray, X-ray, and EUV, to Radio waves). 
Space weather: solar wind and deep space monitoringThis type of mission designates solar wind density, velocity and temperature measurements, and deep space radiation monitoring.  
Space weather: magnetospheric particle monitoringThis capability includes detectors of energetic particles trapped in the magnetosphere or ionosphere. 
Space Weather: ionosphere and magnetosphere monitoringThis type of mission designates observations of ionospheric and magnetospheric status and disturbances,  
Gravity field measuring systemsThe long-wavelength components of the Earth's gravity field are measured by positioning systems and altimeters (radar and lidar). The short-wavelength components are measured by specific missions embarking accelerometers or, in some case, exploiting several satellites in coordinated orbits to measure variations of their relative positions.  
Precise positioningPrecise positioning systems are not only used for spacecraft control and for the provision of satellite-based navigation services (GNSS), they play also a critical role to support satellite altimetry and gravity field observations.  
Data Collection Systems and Search-and-Rescue