Capabilities of Earth Observation
Satellites
Many different types of instruments are
flown on space missions, employing various
measurement technologies and techniques –
both active and passive – that utilise a
wide range of the electromagnetic
spectrum.
CEOS agencies are operating or planning
around 260 satellites with an Earth
observation mission over the next 15 years.
These satellites will carry around 400
different instruments.
This sustained investment by the space
agencies will ensure the provision of
information of unique value in both public
and commercial spheres, derived from the
measurements of a diverse range of
geophysical parameters and phenomena.
Public awareness of the applications of
Earth observation satellites tends to focus
on imagery (through Internet applications
such as Google Earth and Microsoft Live
Local) and on meteorology, combined with the
knowledge that data from meteorological
satellites are used on a daily basis for the
Numerical Weather Prediction models that
drive our weather forecasting
capabilities.
Meteorology is certainly one of the most
established disciplines for application of
Earth observation satellite data, with
satellite-derived information being used
operationally by weather services worldwide.
Dedicated meteorological satellites have
been in operation for several decades,
providing continuous coverage of much of the
globe.
In practice, only 80 missions, or around a
third of those planned for the next 15
years, could be described as having
meteorology as a primary objective. The
other 180 missions will be applied to a
diverse range of research, operational and
commercial activities.
Given the significance of the issues, and
the unique role of satellite Earth
observations, many will be dedicated to
different aspects of climate or
environmental studies. Others will be
employed to assist decision-making in
strategic planning and management of
industrial, economic and natural resources,
including the provision of information
required for sustainable development
strategies. New missions serving operational
needs related to land, ocean and atmospheric
composition have recently been launched or
will be in the near future.
Increased frequency of satellite
measurements, improved satellite and sensor
technology, and easier access and
interpretation of Earth observation data
have all contributed to increased demand for
satellite data and to the reality of new
operational services being established in
the near future for several domains,
including monitoring of key oceanic and
atmospheric parameters.
Information on the various missions and
instruments, their capabilities and their
applications is given in sections 8
(missions) and 9 (instruments).
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For ease of discussion, the different
instruments listed in section 9 may be
considered under the following categories:
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Instrument Categories
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Atmospheric chemistry instruments
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Atmospheric temperature and
humidity sounders
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Cloud profile and rain radars
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Earth radiation budget radiometers
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High-resolution optical imagers
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Imaging multi-spectral radiometers
(visible/infrared)
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Imaging multi-spectral radiometers
(passive microwave)
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| Imaging microwave radars |
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| Lidars |
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| Lightning instruments |
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Multiple direction/polarisation
instruments
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| Ocean colour instruments |
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| Radar altimeters |
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| Scatterometers |
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Gravity, magnetic field and
geodynamic instruments
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Plans for future missions and instruments
include entirely new types of measurement
technology, such as hyperspectral sensors,
cloud radars, lidars and polarimetric
sensors that will provide new insights into
key parameters of atmospheric temperature
and moisture, soil moisture and ocean
salinity. Several new gravity-field missions
aimed at more precise determination of the
marine geoid are also planned. Importantly,
every effort is being made to assure
continuity of existing key measurements for
the generation of long-term datasets. Agency
plans also reveal that future priorities
will include disaster management and studies
of key Earth System processes – the water
cycle, carbon cycle, cryosphere, the role of
clouds and aerosols in global climate
change, and sea level rise.
The following section gives a brief
discussion of the different types of
instruments flown on Earth observation
satellite missions, including a list of the
relevant instruments for each type from the
full catalogue in section 9 a description of
the operational characteristics, and
pointers to the key applications.
Information on specific measurement
parameters is given in section 7.
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