The teledetection indicates, in its broadest meaning, the measurement or the acquisition of information on an object or a phenomenon, via an measuring instrument not having a contact with the studied object. It is the remote use (for example, of a plane, an space engine, a satellite or of a Bateau) of any type of instrument allowing the acquisition of information on the Environnement. One often makes call to instruments such as cameras, laser, radars, sonars, seismographs or gravimeters. The modern teledetection integrates digital processings normally but can just as easily use nonnumerical methods.

The space teledetection , in the field of the Astronautics, is the whole of knowledge and the techniques used to determine the characteristics of the surface and the atmosphere of the Ground or another Planet, by the measurements taken starting from an evolving/moving Space engine remotely suitable of the latter. The term corresponding in English is remote sensing from space .

Principle

This type of method of acquisition uses the measurement of the emitted or reflected electromagnetic radiations normally objects studied in a certain field of frequency (infra-red, visible, microwaves). This is made possible by the fact that the studied objects (plants, houses, surfaces of water or masses of air) emit or think radiation of various wavelengths and intensities depending on their state. Certain instruments of teledetection use sound waves in a similar way, and others measure variations in magnetic fields or gravitating.

Whereas the Astronomie could be regarded as teledetection (push to the extreme), the term teledetection is generally reserved for the ground observations.

Uses

The examples of teledetection are very numerous:
  • the topographic Carte S are often produced using stereographic pairs of air photographs making it possible to recreate an image in three dimensions.
  • the earthquakes are a posteriori localized by comparing Sismogramme S recorded in various places; the relative intensity and the temporal precision of the recording condition the quality of information on the place of the tremor.
  • the digital models of ground can be produced by Interférométrie (using the Radar with synthetic opening), method consisting in recording series of measure of the target starting from a Avion, of a satellite or a Space shuttle. The combination of the data resulting from these measurements offers a detailed chart containing of information on the cover of the ground, the relief or the movement on a centimetric scale. The data generally cover tapes of several kilometers of width.
  • the Precipitation S, the Aircraft S and the Navire S can be detected by Radar S.
  • sea-beds are charted thanks to the use of the Sonar S.

External bonds

  • Observation of Earth ESA
  • International Files for stereo views
  • RemoteSensing.org
  • Maison of the Teledetection in Languedoc-Roussillon
  • General Aerial Photograph Information (U.S. Geological Survey)
  • House of the Teledetection (Montpellier, France)
  • UMR TETIS: Scientific research unit " Territories, Environment, Teledetection and Spatiale" Information;
  • GeoRezo, the gate geomatic: Community site of the disciplines composing the géomatique one - Cartography, geographical Information system, Géomarketing, Teledetection, GPS, Topography…
  • On Channel IRD (video onlines of the Research institute for the Development, IRD) - Discover a station of monitoring of the Amazonian environment assisted by single satellite in Europe and South America.
  • Pole of Observation of continental Surfaces by Teledetection (POSTEL) Center set of themes associating R & D and services to describe the ground and the vegetation starting from the satellite imagery.

See too

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