THE REMOTE SENSING
The
15 m diameter tracking antenna in Kiruna (Sweden). Credits:
ESA – S.CORVAJA
Remote Sensing means observing qualitatively and quantitatively an object from distant.
There is no contact with the object and the electromagnetic radiation reflected, transmitted or emitted by the object is studied. Thus, it is possible to measure, analyze and know the characteristics of the observed object. This can be achieved by special techniques and instruments that take pictures or acquire numerical data to be processed on the Earth.
The tools that are used to observe in depth an object are called sensors and they are placed on means of transport called platforms (balloons, airplanes, satellites, etc.). Typical information that can be obtained on the planet Earth by the satellite remote sensing, are:
the evolution of the ozone hole
the increase of the deforestation
the rise of the deserts
the layer and the thickness of the clouds
The key steps of a satellite remote sensing process are:
1. The satellite acquires the data, stores them and then forwards them by radio signals to the receiving stations on the Earth.
2. The data received by stations on the Earth are processed and subject to a control process for needed correction.
Sometimes the satellite transmits the data to others satellites, which in turn retransmit the data to the Earth stations.