remote sensing
ERS-2 is largely identical to ERS-1. The platform is based on the design developed for the French Satellite Pour l'Observation de la Terre (SPOT; satellite for Earth observation) with the payload electronics accommodated in a box-shaped housing on the platform. Antennae are attached to a bearing structure.
Gathering and recording information from a distance. Aircraft and satellites can observe a planetary surface or atmosphere, and space probes have sent back photographs and data about planets as distant as Neptune. Remote sensing usually refers to gathering data of the electromagnetic spectrum (such as visible light, ultraviolet light, and infrared light). In archaeology, surface survey techniques provide information without disturbing subsurface deposits.
Remote sensing is most commonly taken to refer to the process of photographing the Earth's surface with orbiting satellites. Satellites such as Landsat have surveyed all of the Earth's surface from orbit. Computer processing of data obtained by their scanning instruments, and the application of so-called false colours (generated by computer), have made it possible to reveal surface features invisible in ordinary light. This has proved valuable in agriculture, forestry, and urban planning, and has led to the discovery of new deposits of minerals.
| With a simple aerial, receiver, and software it is possible to download images straight on to a personal computer – helping amateur meteorologists, for example, to make weather forecasts. |
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