REMOTE SENSING

REMOTE SENSING:

Remote sensing is acquiring information about an object, area or phenomenon without coming in contact of it. Aerial photography is also called remote sensing. Human remote sensing organs are eyes(vision), ears(hearing) and nose(smelling). Electromagnetic energy i.e., light energy is used for remote sensing.

ELECTROMAGNETIC ENERGY:

Electromagnetic wave is made up of fluctuating fields-electric and magnetic perpendicular to each other and to the direction of propagation, therefore named as electromagnetic energy.

• EM waves have three basic parameters c=λf, where c denotes velocity, λ denotes the wavelength and f denotes frequency.
• EM waves travel with the velocity of light i.e.,  3.00×10⁸ m/s .
• Wavelength is the length along the direction of propagation between two identical points on two adjacent waves and denotes one cycle.
•  Frequency is the number of cycles of wave that pass through a fixed point in one second. Its unit is hertz (Hz) = one cycle per sec per second.