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INDICE DEL TUTORIAL:
1.
Definición
3. Interacción
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THE OBSERVATION PLATFORMS |
OTROS ITEMS DE INTERES Imágenes satelitales y seguros ¿Qué es la percepción remota?
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Historically the remote sensors par excellence were the plate or the photographic film on aerial platforms, but in the last decades they had to coexist with the electronic sensors, more and more numerous and sophisticated, mounted on suborbital and satellite platforms. The remote sensing from aerial platforms, with photographic films or electronic sensors although continues constituting a very valuable source of information, as of 1960 had to begin to share his rank of applications with the remote sensing technologies from satelite platforms. In effect, until 1946 the remote sensing fundamentally took place from airplanes or globes. In 1946 the first photographies were taken from V-2 rockets captured the to the Germans and such experiences were decisive to illustrate the potential value of the photography from orbital altitudes. This mentioned potential became more remarkable through the space missions as of 1961: Mercury, Gemini and Apolo. Apolo 9, particulary, made the first experience of multispectral orbital photography for the study of the terrestrial resources. These experiences were continued in next missions (Skylab, the Apolo-Soyuz Project Test, etc.). Nevertheless, year 1972 marks a landmark in the space race: it was in this year that the U.S.A. sent in a vehicle Delta the first of a series of optical satellites specially destined to the terrestrial resources monitoring. This series, that denominated ERTS (Earth Resources Technology Satellites) was after renamed LANDSAT. Satellites of this series,LANDSAT-5 and the LANDSAT-7 sill remain operatives. As well France, with the participation of Sweden and Belgium, sent in 1986 in an Ariane vehicle the first satellite of series SPOT (Systeme Pour l'Observation of the Terre) continuing operatives the SPOT-2 and the SPOT-4. At the moment there are numerous satellite platforms similar to LANDSAT and SPOT pertaining to different countries (the U.S.A., India, Russia, Japan, etc.). There are also other satelite systems full applied to meteorological and environmental studies, like for example, those of series NOAA (National Oceanic and Atmospheric Administration) and meteorological the geostationary ones like those of series GOES (Geostationary Operational Environmental Satellite) and METEOSAT. It would be very extensive for us to refer here about the diversity of the orbital platforms of observation, at the moment in orbit, but we can say that the development that began in the decade of 1960 has returned vertiginous. Different factors are conditional this behavior that has taken the Remote Perception to its truely commercial stage. One of such factors was the liberation for civil uses, particularly soon of the aim of the Cold War, of technology reserved until then for military use. It must be indicated that the mentioned satellite systems can simultaneously register the terrestrial images in several spectral bands, usually located in the regions visible and near infrared, middle infrared and thermal infrared of the electromagnietic spectra. This allows to discriminate the nature of the terrestrial objects and to even classify them. The systems optical-by telescope of these satellites focus the terrestrial scenes on adjustments of sensible detectors of solid state to the spectral regions for which it is desired to register the images. The analogical signals generated by the detectors are digitized on board of the satellite for their broadcasting to terrestrial ground stations.
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