Remote Sensing
Contributors:
Bichlien Hoang
Ashley Caudill
Originally published on the IEEE Emerging Technology portal, 2006 - 2012.
Visit: http://www.ieee.org/go/emergingtech
Taking a closer look from a distance is the concept behind remote sensing, broadly defined as a method
of obtaining information about properties of an object without coming into physical contact with that object. [1]
A more specific definition of remote sensing relates to studying the environment from a distance using techniques
such as satellite imaging, aerial photography, and radar.
Remote sensors gather information by measuring the electromagnetic radiation that is reflected, emitted and absorbed
by objects in various spectral regions, from gamma-rays to radio waves. To measure this radiation, both active and
passive remote sensors are used. Passive systems generally consist of an array of sensors which record the amount of
electromagnetic radiation emitted by the surface being studied. Active systems transmit a pulse of energy to the object
being studied and measure the radiation that is reflected or backscattered from that object. Passive radiometric
methods of remote sensing technology include: imaging radiometer, spectrometer and spectroradiometer. Radar,
scatterometer, lidar and laser altimeter are examples of active remote sensor technologies. [2]
While the majority of remote sensing technologies utilize electromagnetic radiation for measurements, other methods
use seismic waves or acoustics. Sonar (sound navigation and ranging) technology is used to collect measurements from
the sea floor by collecting point or raster data derived from the strength and time of the acoustic return. The National
Oceanic and Atmospheric Association (NOAA) uses single and multibeam sonar for numerous applications like mapping
seafloor geology, field verifying other remotely sensed data sets, navigation, disaster recovery and salvage, and habitat
studies, among other uses. [3]
The beginnings of remote sensing technology are based in photography. The first aerial images of the earth were
captured using cameras attached to balloons and kites in the mid-nineteenth century. During World War I aerial views
captured by cameras mounted on airplanes were used for military reconnaissance. This method of aerial photography
became the standard for depicting the earth’s surface from a vertical (looking straight down) or oblique (at various
angles, generally less than 45°) perspective from that time until the 1960s. [4]
Satellites developed by Russian and American space programs expanded the field of vision in the 1960s by obtaining
views from beyond Earth’s atmosphere. Landstat, Nimbus, ERS, RADARSAT and UARS are satellite programs used for
earth observation. Images collected by NASA’s Landsat satellite program, first launched in 1972, are used to monitor a
number of environmental factors including water quality, glacier recession, sea ice movement, invasive species
encroachment, coral reef health, land use change, deforestation rates and population growth. Satellite imagery is also
used to help assess damage from natural disasters such as fires, floods, and tsunamis, and subsequently, plan disaster
relief and flood control programs. [5]
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Remote Sensing
Contributors:
Bichlien Hoang
Ashley Caudill
Originally published on the IEEE Emerging Technology portal, 2006 - 2012.
Visit: http://www.ieee.org/go/emergingtech
Remote sensing methods are used to gain a better understanding of the Earth and its functions. A Global Earth
Observation System of Systems (GEOSS) is being developed to connect earth observation systems around
the world. A comprehensive and coordinated system of earth observations could lead to better management
of environmental data and could fulfill numerous societal benefits including:
Reducing loss of life and property from natural and human-induced disasters.
Understanding environmental factors affecting human health and well-being.
Improving management of energy resources.
Understanding, assessing, predicting, mitigating, and adapting to climate variability and change.
Improving water resource management through better understanding of the water cycle.
Improving weather information, forecasting and warning.
Improving the management and protection of terrestrial, coastal and marine ecosystems.
Supporting sustainable agriculture and combating desertification.
Understanding, monitoring and conserving biodiversity. [6]
The Global Earth Observation System of Systems (GEOSS) 10-Year Implementation Plan encourages the adoption of
international standards to achieve interoperability among diverse systems. IEEE Geoscience and Remote Sensing
Society has identified the need to create standards for standards for collecting, processing, storing, and disseminating
shared metadata, data, and derived products. [7]
References
[1] American Meteorology Society. “Glossary of Meteorology.”
[2] NASA. “Earth Observatory Library: Remote Sensing.”
[3] NOAA Coastal Services Center. “Remote Sensing for Coastal Management.”
[4] NASA. “The Remote Sensing Tutorial.”
[5] NASA. “The Numbers Behind Landsat.”
[6] GEO-Group on Earth Observations. “Societal Benefits.”
[7] IEEE Geoscience and Remote Sensing Society. “GEOSS Standards.”
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