Thursday, August 4, 2016

Interaction of EMR with Earth's surface

The interaction of Electro-magnetic radiation (EMR) with the atmosphere and the earth's surface play a very important role in Remote sensing. Each molecule has a set of absorption bands in the electromangetic spectrum. Hence, only the wavelength regions outside the absorption bands of atmospheric gases can be used for remote sensing. These regions are known as Atmospheric Transmission Windows.
These windows are found in the visible, near infrared, certain bands of thermal infrared and microwave region.
The figure below shows the fate of atmospheric radiation
The gases in the atmosphere interact with solar irradiation and with the radiation reflected from the Earth's surface. The electromagnetic radiation (EMR ) will experience varying degrees of transmission, absorption, emittance and/or scattering.