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For the purported psychic ability to sense remotely, see Remote viewing Psychic, from the Greek psychikos meaning mental, of the soul (in turn derived from psyche meaning soul, mind), is a term used to describe phenomena or abilities that are said to originate from the brain but which transcend its confines. ...
Remote viewing is the purported ability for a viewer to gather information on a remote target consisting of an object, place, or person, etc. ...
In the broadest sense, remote sensing is the short or large-scale acquisition of information of an object or phenomenon, by the use of either recording or real-time sensing device(s) that is not in physical or intimate contact with the object (such as by way of aircraft, spacecraft, satellite, buoy, or ship). In practice, remote sensing is the stand-off collection through the use of a variety of devices for gathering information on a given object or area. Thus, Earth observation or weather satellite collection platforms, ocean and atmospheric observing weather buoy platforms, monitoring of a pregnancy via ultrasound, Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET), and space probes are all examples of remote sensing. In modern usage, the term generally refers to the use of imaging sensor technologies including but not limited to the use of instruments aboard aircraft and spacecraft, and is distinct from other imaging-related fields such as medical imaging. Download high resolution version (399x832, 94 KB)Death valley as seen from the Space Shuttles synthetic aperture radar instrument. ...
Download high resolution version (399x832, 94 KB)Death valley as seen from the Space Shuttles synthetic aperture radar instrument. ...
The surface of Venus, as imaged by the Magellan probe using SAR Synthetic aperture radar (SAR) is a form of radar in which sophisticated post-processing of radar data is used to produce a very narrow effective beam. ...
Death Valley is a valley in the U.S. state of California, and is the location of the lowest elevation in North America at -282 ft (86 m). ...
Polarimetry is the measurement of the polarisation of light; a polarimeter is the scientific instrument used to make these measurements. ...
Look up aircraft in Wiktionary, the free dictionary. ...
The Space Shuttle Discovery as seen from the International Space Station. ...
An Earth observation satellite, ERS 2 For other uses, see Satellite (disambiguation). ...
A sea lion on navigational buoy #14 in San Diego Harbor Green can #11 near the mouth of the Saugatuck river. ...
Italian Full rigged ship Amerigo Vespucci in New York Harbor, 1976 A ship is a large watercraft capable of offshore navigation. ...
Earth Observation refers to the use of sensors onboard artificial satellites to measure properties of the Earth. ...
GOES-8, a United States weather satellite. ...
Weather buoys are instruments which collect weather and ocean data within the worlds oceans. ...
Ultrasound is a form of cyclic sound pressure with a frequency greater than the upper limit of human hearing, this limit being approximately 20 kilohertz (20,000 hertz). ...
Magnetic Resonance Image showing a median sagittal cross section through a human head. ...
Image of a typical positron emission tomography (PET) facility Positron emission tomography (PET) is a nuclear medicine medical imaging technique which produces a three-dimensional image or map of functional processes in the body. ...
Unmanned space missions are those using remote-controlled spacecraft. ...
Medical imaging designates the ensemble of techniques and processes used to create images of the human body (or parts thereof) for clinical purposes (medical procedures seeking to reveal, diagnose or examine disease) or medical science (including the study of normal anatomy and function). ...
There are two kinds of remote sensing. Passive sensors detect natural energy (radiation) that is emitted or reflected by the object or surrounding area being observed. Reflected sunlight is the most common source of radiation measured by passive sensors. Examples of passive remote sensors include film photography, infra-red, charge-coupled devices and radiometers. Active collection, on the other hand, emits energy in order scan objects and areas whereupon a passive sensor then detects and measures the radiation that is reflected or backscattered from the target. RADAR is an example of active remote sensing where the time delay between emission and return is measured, establishing the location, height, speed and direction of an object.
Remote sensing makes it possible to collect data on dangerous or inaccessible areas. Remote sensing applications include monitoring deforestation in areas such as the Amazon Basin, the effects of global warming on glaciers and Arctic and Antarctic regions, and depth sounding of coastal and ocean depths. Military collection during the cold war made use of stand-off collection of dangerous border areas. Remote sensing also replaces costly and slow collection on the ground, ensuring in the process that areas or objects are not disturbed.
Orbital platforms collect and transmit data from different parts of the electromagnetic spectrum, in conjunction with smaller scale aerial or ground-based sensing and analysis provides researchers with enough information to monitor trends such as el niño and other natural long and short term phenomena. Other uses include different areas of earth sciences such as natural resource management, agricultural fields such as land usage and conservation, and national security, both overhead, ground-based and stand-off collection on border areas.[1].
Data acquisition techniques
The basis for multi-spectral collection and analysis is that of examined areas or objects that reflect or emit radiation that stand out from surrounding areas.
Applications of Multi-spectral data - Radar Conventional radar is mostly associated with aerial traffic control, early warning, and certain large scale meteorical data. Doppler radar is used by local law enforcements' monitoring of speed limits and in enhanced meteorological collection such as wind speed and direction within weather systems. Other types of active collection includes plasmas in the ionosphere). Interferometric synthetic aperture radar is used to produce precise digital elevation models of large scale terrain (See RADARSAT, Magellan).
- Laser and radar altimeters on satellites have provided a wide range of data. By measuring the bulges of water caused by gravity, they map features on the seafloor to a resolution of a mile or so. By measuring the height and wave-length of ocean waves, the altimeters measure wind speeds and direction, and surface ocean currents and directions.
- LIDAR Light Detection And Ranging - is well known in the examples of weapon ranging, laser illuminated homing of projectiles. LIDAR is used to detect and measure the concentration of various chemicals in the atmosphere, while airborne LIDAR can be used to measure heights of objects and features on the ground more accurately than with radar technology.
- Radiometers and photometers are the most common instrument in use, collecting reflected and emitted radiation in a wide range of frequencies. The most common are visible and infrared sensors, followed by microwave, gamma ray and rarely, ultraviolet. They may also be used to detect the emission spectra of various chemicals, providing data on chemical concentrations in the atmosphere.
- Stereographic pairs of aerial photographs have often been used to make Topographic maps by Imagery Analysts, Terrain Analysts in trafficability and highway departments for potential routes.
- Simultaneous multi-spectral platforms such as Landsat have been in use since the 70's.these thematic mappers take images in multiple wavelengths of electro-magnetic radiation (multi-spectral) and are usually found on earth observation satellites, including (for example) the Landsat program or the IKONOS satellite. Maps of land cover and land use from thematic mapping can be used to prospect for minerals, detect or monitor land usage, deforestation, and examine the health of indigenous plants and crops, including entire farming regions or forests.
This long range radar antenna, known as ALTAIR, is used to detect and track space objects in conjunction with ABM testing at the Ronald Reagan Test Site on the Kwajalein atoll. ...
A plasma lamp, illustrating some of the more complex phenomena of a plasma, including filamentation. ...
Relationship of the atmosphere and ionosphere The ionosphere is the uppermost part of the atmosphere, distinguished because it is ionized by solar radiation. ...
For the town in Russia, see Insar. ...
3D rendering of a DEM of Tithonium Chasma on Mars A digital elevation model (DEM) is a digital representation of ground surface topography or terrain. ...
RADARSAT are Canadian Earth observation satellites: RADARSAT-1, launched 1995 RADARSAT-2, to be launched December 2006 ...
Magellan spacecraft at Kennedy Space Center The Magellan spacecraft carried out a mission from 1989-1994, orbiting Venus from 1990-1994. ...
Diagram showing the face of a three-pointer sensitive aircraft altimeter displaying altitude in feet. ...
This article or section does not adequately cite its references or sources. ...
A radiometer is a device used to measure the radiant flux or power in electromagnetic radiation. ...
In the broadest sense, a photometer is any instrument used to measure illuminance or irradiance. ...
A materials emission spectrum is the amount of electromagnetic radiation of each frequency it emits when it is heated (or more generally when it is excited). ...
Stereo card image modified for crossed eye viewing. ...
Aerial photography is the taking of photographs from above with a camera mounted on an aircraft, balloon, rocket, kite or similar vehicle. ...
Example of a topographic map with contour lines Part of the same map in a perspective shaded relief view illustrates how the contour lines of the original follow the terrain Topographic maps are a variety of map characterized by large-scale detail and quantitative representation of relief, usually using contour...
Earth observation satellites are satellites specifically designed to observe Earth from orbit, similar to reconnaissance satellites but intended for non-military uses such as environmental monitoring, meteorology, map making etc. ...
The Landsat program is the longest running enterprise for acquisition of imagery of Earth from space. ...
IKONOS is a commercial earth observation satellite that collects high-resolution imagery at 1- and 4-meter resolution. ...
Geodetic - Overhead geodetic collection was first used in aerial submarine detection and gravitational data used in military maps. This data reveal minute perturbations in the Earth's gravitational field (geodesy) may be used to determine changes in the mass distribution of the Earth, which in turn may be used for geological or hydrological studies.
The gravitational field is a field (physics), generated by massive objects, that determines the magnitude and direction of gravitation experienced by other massive objects. ...
It has been suggested that geodetic system be merged into this article or section. ...
Acoustic and near-acoustic - Passive;Sonar is used for detecting, ranging and measurements of underwater objects and terrain.
- Seismograms taken at different locations can locate and measure earthquakes (after they occur) by comparing the relative intensity and precise timing.
- Active; pulses are used by geologists to detect oil fields.
In order to coordinate a series of large-scale observations, most sensing systems depend on the following; platform location, what time it is, and the rotation and orientation of the sensor. High-end instruments now often use positional information from satellite navigation systems. The rotation and orientation is often provided within a degree or two with electronic compasses. Compasses can measure not just azimuth (i.e. degrees to magnetic north), but also altitude (degrees above the horizon), since the magnetic field curves into the Earth at different angles at different latitudes. More exact orientations require gyroscopic-aided orientation, periodically realigned by different methods including navigation from stars or known benchmarks. The F70 type frigates (here, La Motte-Picquet) are fitted with VDS (Variable Depth Sonar) type DUBV43 or DUBV43C towed sonars SONAR (SOund Navigation And Ranging) — or sonar — is a technique that uses sound propagation under water (primarily) to navigate, communicate or to detect other vessels. ...
Seismographs (in Greek seismos = earthquake and graphein = write) are used by seismologists to record seismic waves. ...
An earthquake is the result from the sudden release of stored energy in the Earths crust that creates seismic waves. ...
It has been suggested that this article or section be merged into Global Navigation Satellite System. ...
An inertial navigation system measures the position and altitude of a vehicle by measuring the accelerations and rotations applied to the systems inertial frame. ...
Resolution impacts collection and is best explained with the following relationship; less resolution=less detail & larger coverage, More resolution=more detail, less coverage. The skilled management of collection results in cost-effective collection and avoid situations such as the use of multiple high resolution data which tends to clog transmission and storage infrastructure.
Data processing - See also: Inverse problem
Generally speaking, remote sensing works on the principle of the inverse problem. While the object or phenomenon of interest (the state) may not be directly measured, there exists some other variable that can be detected and measured (the observation), which may be related to the object of interest through the use of a data-derived computer model. The common analogy given to describe this is trying to determine the type of animal from its footprints. For example, while it is impossible to directly measure temperatures in the upper atmosphere, it is possible to measure the spectral emissions from a known chemical species (such as carbon dioxide) in that region. The frequency of the emission may then be related to the temperature in that region via various thermodynamic relations. An inverse problem is the task that often occurs in many branches of science and mathematics where the values of some model parameter(s) must be obtained from the observed data. ...
Thermodynamics (Greek: thermos = heat and dynamic = change) is the physics of energy, heat, work, entropy and the spontaneity of processes. ...
The quality of remote sensing data consists of its spatial, spectral, radiometric and temporal resolutions. Spatial resolution refers to the size of a pixel that is recorded in a raster image - typically pixels may correspond to square areas ranging in side length from 1 to 1000 metres. Spectral resolution refers to the number of different frequency bands recorded - usually, this is equivalent to the number of sensors carried by the platform(s). Current Landsat collection is that of seven bands, including several in the infra-red spectrum. The MODIS satellites are the highest resolving at 31 bands. Radiometric resolution refers to the number of different intensities of radiation the sensor is able to distinguish. Typically, this ranges from 8 to 14 bits, corresponding to 256 levels of the gray scale and up to 16,384 intensities or "shades" of colour, in each band. The temporal resolution is simply the frequency of flyovers by the satellite or plane, and is only relevant in time-series studies or those requiring an averaged or mosaic image as in deforesting monitoring. This was first used by the intelligence community where repeated coverage revealed changes in infrastructure, the deployment of units or the modification/introduction of equipment . Cloud cover over a given area or object makes it necessary to repeat the collection of said location. Finally, some people also refer to the "economic resolution", that is, the cost-effective way to manage the collection of data. This example shows an image with a portion greatly enlarged, in which the individual pixels are rendered as little squares and can easily be seen. ...
Suppose the smiley face in the top left corner is an RGB bitmap image. ...
In order to create sensor-based maps, most remote sensing systems expect to extrapolate sensor data in relation to a reference point including distances between known points on the ground. This depends on the type of sensor used. For example, in conventional photographs, distances are accurate in the center of the image, with the distortion of measurements increasing the farther you get from the center. Another factor is that of the platen against which the film is pressed can cause severe errors when photographs are used to measure ground distances. The step in which this problem is resolved is called georeferencing, and involves computer-aided matching up of points in the image (typically 30 or more points per image) which is extrapolated with the use of an established benchmark, "warping" the image to produce accurate spatial data. As of the early 1990s, most satellite images are sold fully georeferenced. To georeference something is used to define its existence in physical space. ...
In addition, images may need to be radiometrically and atmospherically corrected. Radiometric correction gives a scale to the pixel values, e.g. the monochromatic scale of 0 to 255 will be converted to actual radiance values. Atmospheric correction eliminates atmospheric haze by rescaling each frequency band so that its minimum value (usually realised in water bodies) corresponds to a pixel value of 0. The digitizing of data also make possible to manipulate the data by changing gray-scale values.
Interpretation is the critical process of making sense of the data. The first application was that of aerial photographic collection which used the following process; spatial measurement through the use of a light table in both conventional single or stereographic coverage, added skills such as the use of photogrammetry, the use of photomosaics, repeat coverage, Making use of objects' known dimensions in order to detect modifications. Image Analysis is the recently developed automated computer-aided application which is in increasing use.
Old data from remote sensing is often valuable because it may provide the only long-term data for a large extent of geography. At the same time, the data is often complex to interpret, and bulky to store. Modern systems tend to store the data digitally, often with lossless compression. The difficulty with this approach is that the data is fragile, the format may be archaic, and the data may be easy to falsify. One of the best systems for archiving data series is as computer-generated machine-readable ultrafiche, usually in typefonts such as OCR-B, or as digitized half-tone images. Ultrafiches survive well in standard libraries, with lifetimes of several centuries. They can be created, copied, filed and retrieved by automated systems. They are about as compact as archival magnetic media, and yet can be read by human beings with minimal, standardized equipment. An ultrafiche or ultramicrofiche is an exceptionally compact version of a microfiche or microfilm, storing analog data at much higher densities. ...
History
 The TR-1 reconnaissance/surveillance aircraft.
 The 2001 Mars Odyssey Spacecraft used spectrometers and imagers to hunt for evidence of past or present water and volcanic activity on Mars. Beyond the primitive methods of remote sensing our earliest ancestors used (ex.: standing on a high cliff or tree to view the landscape), the modern discipline arose with the development of flight. The balloonist G. Tournachon (alias Nadar) made photographs of Paris from his balloon in 1858. The first tactical use was during the civil war. Messenger pigeons, kites, rockets and unmanned balloons were also used for early images. With the exception of balloons, these first, individual images were not particularly useful for map making or for scientific purposes. USAF U-2 Dragon Lady. ...
USAF U-2 Dragon Lady. ...
Other external images http://mars. ...
Other external images http://mars. ...
Nadar (self-portrait). ...
Systematic aerial photography was developed for military surveillance and reconnaissance purposes beginning in World War I and reaching a climax during the Cold War with the use of modified combat aircraft such as the P-51, P-38, RB-66, F4-C and the SR-71 or specifically designed collection platforms such as the U2/TR-1, A-5 and the OV-1 series both in overhead and stand-off collection. A more recent development is that of increasingly smaller sensor pods such as those used by law enforcement and the military, in both manned and unmanned platforms. The advantage of this approach is that this requires minimal modification to a given airframe. Later imaging technologies would include Infra-red, conventional, doppler and synthetic aperture radar The Denver, Colorado skyline shot from a Cessna. ...
“The Great War †redirects here. ...
For other uses, see Cold War (disambiguation). ...
The development of artificial satellites in the latter half of the 20th century allowed remote sensing to progress to a global scale as of the end of the cold war. Instrumentation aboard various Earth observing and weather satellites such as Landsat, the Nimbus and more recent missions such as RADARSAT and UARS provided global measurements of various data for civil, research, and military purposes. Space probes to other planets have also provided the opportunity to conduct remote sensing studies in extra-terrestrial environments, synthetic aperture radar aboard the Magellan spacecraft provided detailed topographic maps of Venus, while instruments aboard SOHO allowed studies to be performed on the Sun and the solar wind, just to name a few examples. The Landsat program is the longest running enterprise for acquisition of imagery of Earth from space. ...
The Nimbus satellites were second-generation U.S. unmanned spacecraft for meteorological research and development. ...
RADARSAT are Canadian Earth observation satellites: RADARSAT-1, launched 1995 RADARSAT-2, to be launched December 2006 ...
The Upper Atmosphere Research Satellite (UARS) is an orbital 14,500-pound U.S. observatory that made the most extensive study ever conducted of the Earths troposphere, the upper level of the planets envelope of life-sustaining gases which also include the protective ozone layer. ...
Magellan spacecraft at Kennedy Space Center The Magellan spacecraft carried out a mission from 1989-1994, orbiting Venus from 1990-1994. ...
Adjectives: Venusian or (rarely) Cytherean Atmosphere Surface pressure: 9. ...
The Solar and Heliospheric Observatory (SOHO) is a spacecraft that was launched on an Atlas IIAS launch vehicle on 2 December 1995 to study the Sun, and began normal operations in May 1996. ...
“Sol†redirects here. ...
The plasma in the solar wind meeting the heliopause The solar wind is a stream of charged particles (i. ...
Recent developments include, beginning in the 1960s and 1970s with the development of image processing of satellite imagery. Several research groups in Silicon Valley including NASA Ames Research Center, GTE and ESL Inc. developed Fourier transform techniques leading to the first notable enhancement of imagery data. UPIICSA IPN - Binary image Image processing is any form of information processing for which the input is an image, such as photographs or frames of video; the output is not necessarily an image, but can be for instance a set of features of the image. ...
An Earth observation satellite, ERS 2 For other uses, see Satellite (disambiguation). ...
A view of downtown San Jose, the self-proclaimed Capital of Silicon Valley. ...
Aerial View of Moffett Field and NASA Ames Research Center. ...
General Telephone and Electronics (GTE) was the largest of the independent US telephone companies during the days of the Bell System. ...
ESL Incorporated is a high technology U.S. firm engaged in software design, systems analysis and hardware development for the strategic reconnaisance marketplace. ...
In mathematics, the Fourier transform is a certain linear operator that maps functions to other functions. ...
Further reading - Campbell, J.B. (2002). Introduction to remote sensing, 3rd ed., The Guilford Press. ISBN 1-57230-640-8.
- Jensen, J.R. (2000). Remote sensing of the environment: an Earth resource perspective. Prentice Hall. ISBN 0-13-489733-1.
- Lillesand, T.M.; R.W. Kiefer, and J.W. Chipman (2003). Remote sensing and image interpretation, 5th ed., Wiley. ISBN 0-471-15227-7.
- Richards, J.A.; and X. Jia (2006). Remote sensing digital image analysis: an introduction, 4th ed., Springer. ISBN 3-540-25128-6.
- US Army FM series.
- US Army military intelligence museum, FT Huachuca, AZ
See also -
The Denver, Colorado skyline shot from a Cessna. ...
A geographic Information System (GIS) is a system for capturing, storing, analyzing and managing data and associated attributes which are spatially referenced to the earth. ...
Survey equipment used in geomatics Geomatics is the discipline of gathering, storing, processing, and delivering of geographic information, or spatially referenced information. ...
Land cover is the physical material at the surface of the earth. ...
Pictometry International is a Rochester, New York-based company that provides detailed aerial photography. ...
This long range radar antenna, known as ALTAIR, is used to detect and track space objects in conjunction with ABM testing at the Ronald Reagan Test Site on the Kwajalein atoll. ...
To meet Wikipedias quality standards, this article or section may require cleanup. ...
In telecommunication and physics, radiometry is the science of radiation measurement. ...
An Earth observation satellite, ERS 2 For other uses, see Satellite (disambiguation). ...
Partial list of Earth observation satellites by series/program. ...
Technicians work on the Ulysses space probe. ...
Vector Map (VMAP), AKA Vector Smart Map, is a vector based collection of GIS data covering the earth at various detail levels. ...
The term hyperspectral is found in military and remote sensing jargon and denotes, a sensor system observing a target in very different spectral bands, by different types of sensors, e. ...
Geophysical survey refers to the systematic collection of geophysical data for spatial studies. ...
Imagery analysis is the extraction of useful information from bi-dimensional graphic formats, including screen shots. ...
External links Associations and Societies Spatial Agencies Remote Sensing Centres Remote Sensing: Universities - Department of Geomatic Engineering, University College London
Satellites (missions, platforms and sensors) - ADEOS2
- AIM
- ALOS
- Aqua
- ASTER on Terra
- Aura
- AVHRR
- EO-1
- ENVISAT-1
- ERS
- GOES
- ICESAT
- IKONOS
- IRS
- JERS
- Landsat
- MODIS on Terra and Aqua
- OrbView
- Quickbird
- RADARSAT
- SeaWifs
- SPOT Image
- Terra
- TRMM
Tutorials - CCRS Remote Sensing Tutorials
- NASA Remote Sensing Tutorial
Other relevant sites
- Earth Resources Observation and Science (EROS)
- The Earth Observation Handbook (CEOS)
- EOSL's Remote Sensing Group - The Electro-Optical Systems Laboratory at GTRI has extensive expertise in lidar, multispectral and hyperspectral imaging, and geospatial applications.
- General Aerial Photograph Information (U.S. Geological Survey)
- LADSS - Remote Sensing in Agriculture
- RemoteSensingOnLine
- Remote Sensing from Air and Space (pdf)
- [2]
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