Basics of Remote Sensing & GIS


There are Three Types Of Energy 

  1. Conduction 
  2. Convection 
  3. Radiation

Absorption, scattering, reflection and refraction ( for phenomena for light intercept )

Absorption : there are many interaction for absorption, 1350 energy reflect and absorb in atmosphere. 

UV light : stratosphere absorb UV rays. Ozone layer maximum absorb the UV rays.

Atmospheric Window : Certain contain absorb and certain content pass through the spectrometer so it's called atmospheric window.

Scattering ( Spreading ) 

Classification of scattering :  

  1. Selective scattering 
  2. Non selective scattering

In selective scattering there are three types : 

  1. Relays scattering
  2. Mines scattering
  3. Raman scatering

#1. Selective scattering  

Where particle size is 5 micrometer and the wavelength of the light is 5 m so light is not scatter.

But where the particle size 10 micrometre and wavelength of the light is 5 m so light is reflect.

1. Relays scattering ( Molecular Scattering )

Much more smaller than the light ( 550 microwavelength) 

Source is very high and particle ( less than > 1 time ) 

Upper atmosphere ( 25 km from sky ) 

Atmosphere blue because of Relays scattering. 

Scattering inversely proportional to wavelength of the light. ( Well 550 wavelength of the light then 60 time higher scattering happen ) 

2. Mie scattering ( non molecular scattering )  

The particle size is very high and and it's happened below the atmosphere it's call Mie scattering. 

( 0.1 to 10 Times ) particle size it will give you mie scattering. 

Lower atmosphere up to 4 to 5 km. 

3. Raman scatering ( particle size may Les and high doesn't matter ) 

Light intensity either increase so Raman scattering or may be Decrease.

#2. Non selective scattering 

( light source more than 10 times larger so non selective scattering happens ) 

It is not in organised form

Note : Relays scattering > Raman scatering > mie scattering  ( particle size always ... increase ) 

Refreation :

When light change their medium the light pass through one phase to another phase it's call reflection ( due to density ) Atmospheric Simring due to Refreation. 

Reflection : 

( The medium are same )  it will not generated data on particular surface.

4 phenomena for light interact  : 

Radiant flux ( Albido or Surface reflux) vot/ meter ^2

Radiant energy difference its call radiant flux.

Spectroscopy : any object how react with electromagnetic... 

Spector: every object it's unique because every chemical composition are different. 

Observance and Reflection both are in reversible