Earth observation

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Earth observation (EO) is the gathering of information about the physical, chemical, and biological systems of the planet Earth. [1] It can be performed via remote-sensing technologies (Earth observation satellites) or through direct-contact sensors in ground-based or airborne platforms (such as weather stations and weather balloons, for example). [2] [3]

Contents

According to the Group on Earth Observations (GEO), the concept encompasses both "space-based or remotely-sensed data, as well as ground-based or in situ data". [4] Earth observation is used to monitor and assess the status of and changes in natural and built environments. [1]

Terminology

In Europe, Earth observation has often been used to refer to satellite-based remote sensing, [1] but the term is also used to refer to any form of observations of the Earth system, including in situ and airborne observations, for example. The GEO, which has over 100 member countries and over 100 participating organizations, uses EO in this broader sense. [4]

In the US, the term remote sensing was used since the 1960s [5] to refer to satellite-based remote sensing. Remote sensing has also been used more broadly for observations using any form of remote sensing technology, including airborne sensors and even ground-based sensors such as cameras. [5] Perhaps the least ambiguous term to use for satellite-based sensors is satellite remote sensing (SRS), an acronym which is gradually starting to appear in the literature. [5] [6]

Types

Earth observations may include: [3] [5]

Applications

Just as Earth observations consist of a wide variety of possible elements, they can be applied to a wide variety of uses. Some of the specific applications of Earth observations are: [6]

The quality and quantity of Earth observations continue to mount rapidly. In addition to the ongoing launch of new remote-sensing satellites, increasingly sophisticated in situ instruments located on the ground, on balloons and airplanes, and in rivers, lakes and oceans, are generating increasingly comprehensive, nearly real-time observations.

In 2017 [8] Earth observation have become increasingly technologically sophisticated. It has also become more important due to the dramatic impact that modern human civilization is having on the world and the need to minimize negative effects (e.g. geohazards), [8] along with the opportunities such observation provides to improve social and economic well-being.

See also

Related Research Articles

<span class="mw-page-title-main">Earth observation satellite</span> Satellite specifically designed to observe Earth from orbit

An Earth observation satellite or Earth remote sensing satellite is a satellite used or designed for Earth observation (EO) from orbit, including spy satellites and similar ones intended for non-military uses such as environmental monitoring, meteorology, cartography and others. The most common type are Earth imaging satellites, that take satellite images, analogous to aerial photographs; some EO satellites may perform remote sensing without forming pictures, such as in GNSS radio occultation.

<span class="mw-page-title-main">Envisat</span> ESA Earth observation satellite (2002–2012)

Envisat is a large Earth-observing satellite which has been inactive since 2012. It is still in orbit and considered space debris. Operated by the European Space Agency (ESA), it was the world's largest civilian Earth observation satellite.

<span class="mw-page-title-main">Remote sensing</span> Acquisition of information at a significant distance from the subject

Remote sensing is the acquisition of information about an object or phenomenon without making physical contact with the object, in contrast to in situ or on-site observation. The term is applied especially to acquiring information about Earth and other planets. Remote sensing is used in numerous fields, including geophysics, geography, land surveying and most Earth science disciplines ; it also has military, intelligence, commercial, economic, planning, and humanitarian applications, among others.

<span class="mw-page-title-main">Landsat program</span> American network of Earth-observing satellites for international research purposes

The Landsat program is the longest-running enterprise for acquisition of satellite imagery of Earth. It is a joint NASA / USGS program. On 23 July 1972, the Earth Resources Technology Satellite was launched. This was eventually renamed to Landsat 1 in 1975. The most recent, Landsat 9, was launched on 27 September 2021.

<span class="mw-page-title-main">Landsat 1</span> First satellite of the United States Landsat program, active 1972–78

Landsat 1 (LS-1), formerly named ERTS-A and ERTS-1, was the first satellite of the United States' Landsat program. It was a modified version of the Nimbus 4 meteorological satellite and was launched on July 23, 1972, by a Delta 900 rocket from Vandenberg Air Force Base in California.

The Earth Observing System (EOS) is a program of NASA comprising a series of artificial satellite missions and scientific instruments in Earth orbit designed for long-term global observations of the land surface, biosphere, atmosphere, and oceans. Since the early 1970s, NASA has been developing its Earth Observing System, launching a series of Landsat satellites in the decade. Some of the first included passive microwave imaging in 1972 through the Nimbus 5 satellite. Following the launch of various satellite missions, the conception of the program began in the late 1980s and expanded rapidly through the 1990s. Since the inception of the program, it has continued to develop, including; land, sea, radiation and atmosphere. Collected in a system known as EOSDIS, NASA uses this data in order to study the progression and changes in the biosphere of Earth. The main focus of this data collection surrounds climatic science. The program is the centrepiece of NASA's Earth Science Enterprise.

Aerial archaeology is the study of archaeological remains by examining them from a higher altitude. In present day, this is usually achieved by satellite images or through the use of drones.

<span class="mw-page-title-main">Satellite imagery</span> Images taken from an artificial satellite

Satellite images are images of Earth collected by imaging satellites operated by governments and businesses around the world. Satellite imaging companies sell images by licensing them to governments and businesses such as Apple Maps and Google Maps.

<span class="mw-page-title-main">Landsat 3</span> American Earth-observing satellite launched in 1978 as part of the Landsat program

Landsat 3 is the third satellite of the Landsat program. It was launched on March 5, 1978, with the primary goal of providing a global archive of satellite imagery. Unlike later Landsat satellites, Landsat 3 was managed solely by NASA. Landsat 3 decommissioned on September 7, 1983, beyond its design life of one year. The data collected during Landsat 3's lifetime was used by 31 countries. Countries that cannot afford their own satellite are able to use the data for ecological preservation efforts and to determine the location of natural resources.

<span class="mw-page-title-main">Solar Orbiter</span> European space-based solar observatory

The Solar Orbiter (SolO) is a Sun-observing probe developed by the European Space Agency (ESA) with a National Aeronautics and Space Administration (NASA) contribution. Solar Orbiter, designed to obtain detailed measurements of the inner heliosphere and the nascent solar wind, will also perform close observations of the polar regions of the Sun which is difficult to do from Earth. These observations are important in investigating how the Sun creates and controls its heliosphere.

<span class="mw-page-title-main">MERIS</span>

MEdium Resolution Imaging Spectrometer (MERIS) was one of the main instruments on board the European Space Agency (ESA)'s Envisat platform. The sensor was in orbit from 2002 to 2012. ESA formally announced the end of Envisat's mission on 9 May 2012.

Atmospheric sounding or atmospheric profiling is a measurement of vertical distribution of physical properties of the atmospheric column such as pressure, temperature, wind speed and wind direction, liquid water content, ozone concentration, pollution, and other properties. Such measurements are performed in a variety of ways including remote sensing and in situ observations.

<span class="mw-page-title-main">Copernicus Programme</span> Programme of the European Commission

Copernicus is the Earth observation component of the European Union Space Programme, managed by the European Commission and implemented in partnership with the EU Member States, the European Space Agency (ESA), the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), the European Centre for Medium-Range Weather Forecasts (ECMWF), the Joint Research Centre (JRC), the European Environment Agency (EEA), the European Maritime Safety Agency (EMSA), Frontex, SatCen and Mercator Océan.

<span class="mw-page-title-main">Ocean color</span> Explanation of the color of oceans and ocean color remote sensing

Ocean color is the branch of ocean optics that specifically studies the color of the water and information that can be gained from looking at variations in color. The color of the ocean, while mainly blue, actually varies from blue to green or even yellow, brown or red in some cases. This field of study developed alongside water remote sensing, so it is focused mainly on how color is measured by instruments.

<span class="mw-page-title-main">Meteorological instrumentation</span> Measuring device used in meteorology

Meteorological instruments, including meteorological sensors, are the equipment used to find the state of the atmosphere at a given time. Each science has its own unique sets of laboratory equipment. Meteorology, however, is a science which does not use much laboratory equipment but relies more on on-site observation and remote sensing equipment. In science, an observation, or observable, is an abstract idea that can be measured and for which data can be taken. Rain was one of the first quantities to be measured historically. Two other accurately measured weather-related variables are wind and humidity. Many attempts had been made prior to the 15th century to construct adequate equipment to measure atmospheric variables.

The Group on Earth Observations (GEO) coordinates international efforts to build a Global Earth Observation System of Systems (GEOSS). It links existing and planned Earth observation systems and supports the development of new ones in cases of perceived gaps in the supply of environment-related information. It aims to construct a global public infrastructure for Earth observations consisting of a flexible and distributed network of systems and content providers.

<span class="mw-page-title-main">Sentinel-3</span> Earth observation satellite series

Sentinel-3 is an Earth observation heavy satellite series developed by the European Space Agency as part of the Copernicus Programme. It currently consists of 2 satellites: Sentinel-3A and Sentinel-3B. After initial commissioning, each satellite was handed over to EUMETSAT for the routine operations phase of the mission. Two recurrent satellites— Sentinel-3C and Sentinel-3D— will follow in approximately 2024 and 2028 respectively to ensure continuity of the Sentinel-3 mission.

<span class="mw-page-title-main">ESA Vigil</span> 2018 ESA concept study for a solar weather mission

The Vigil mission, formerly known as Lagrange, is a Space weather weather mission developed by European Space Agency. The mission will provide the ESA Space Weather Office with instruments able to monitor the Sun, its solar corona and interplanetary medium between the Sun and Earth, to provide early warnings of increased solar activity, to identify and mitigate potential threats to society and ground, airborne and space based infrastructure as well as to allow 4 to 5 days space weather forecasts. To this purpose the Vigil mission will place for the first time a spacecraft at Sun-Earth Lagrange point 5 (L5) from where it would get a 'side' view of the Sun, observing regions of solar activity on the solar surface before they turn and face Earth.

Remote sensing in oceanography is a widely used observational technique which enables researchers to acquire data of a location without physically measuring at that location. Remote sensing in oceanography mostly refers to measuring properties of the ocean surface with sensors on satellites or planes, which compose an image of captured electromagnetic radiation. A remote sensing instrument can either receive radiation from the earth’s surface (passive), whether reflected from the sun or emitted, or send out radiation to the surface and catch the reflection (active). All remote sensing instruments carry a sensor to capture the intensity of the radiation at specific wavelength windows, to retrieve a spectral signature for every location. The physical and chemical state of the surface determines the emissivity and reflectance for all bands in the electromagnetic spectrum, linking the measurements to physical properties of the surface. Unlike passive instruments, active remote sensing instruments also measure the two-way travel time of the signal; which is used to calculate the distance between the sensor and the imaged surface. Remote sensing satellites often carry other instruments which keep track of their location and measure atmospheric conditions.

References

  1. 1 2 3 "Earth observation". joint-research-centre.ec.europa.eu. Retrieved 2022-09-23.
  2. "Aims and Scope". International Journal of Applied Earth Observation and Geoinformation. Elsevier. Retrieved 2012-07-20.
  3. 1 2 "Newcomers Earth Observation Guide | ESA Business Applications". business.esa.int. Retrieved 2022-09-23.
  4. 1 2 "GEO at a Glance" . Retrieved 2020-08-25.
  5. 1 2 3 4 Pennisi, Elizabeth (10 September 2021). "Meet the Landsat pioneer who fought to revolutionize Earth observation". Science. 373 (6561): 1292. doi:10.1126/science.acx9080. S2CID   239215521.
  6. 1 2 Eklundh, Lars. "Remote sensing and Earth observation". www.nateko.lu.se. Retrieved 2022-09-27.
  7. Ashley Strickland, CNN (16 Dec 2022) 'Game changer' satellite will measure most of the water on the planet
  8. 1 2 3 4 Tomás, Roberto; Li, Zhenhong (2017-02-24). "Earth Observations for Geohazards: Present and Future Challenges". Remote Sensing. 9 (3): 194. Bibcode:2017RemS....9..194T. doi: 10.3390/rs9030194 . ISSN   2072-4292.