Interaction Between Radiation and the Material
Download
1 / 43

Interaction Between Radiation and the Material - PowerPoint PPT Presentation


  • 139 Views
  • Uploaded on

Interaction Between Radiation and the Material. Prof. Arnon Karnieli The Remote Sensing Laboratory Jacob Blaustein Institute for Desert Research Ben-Gurion University of the Negev Sede-Boker Campus 84990, ISRAEL. Radiation Interaction with a Matter. Transmission.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Interaction Between Radiation and the Material' - ardice


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript

Interaction Between Radiation and the Material

Prof. Arnon Karnieli

The Remote Sensing Laboratory

Jacob Blaustein Institute for Desert Research

Ben-Gurion University of the Negev

Sede-Boker Campus 84990, ISRAEL



Transmission
Transmission

  • Incident radiation passes through the material without attenuation

  • Change in the direction of radiation is given by the index of refraction of the material


Refraction and diffraction
Refraction and Diffraction

Transmitted waves are refracted or diffracted:

Refraction occurs when an electromagnetic wave crosses a boundary from one medium to another. A wave entering a medium at an angle will change direction.

Diffraction refers to the "bending of waves around an edge" of an object. Diffraction depends on the size of the object relative to the wavelength of the wave.


Index of refraction
Index of Refraction

1

2

Index of refraction (n) is the ratio of the speed of light in vacuum relative to the speed of light through the material

Snell’s law describes refraction angles:


Absorption
Absorption

- The material is opaque to incident radiation

- A portion of EMR is converted to heat (re-radiated)


Reflection
Reflection

Reflectance

- Diffuse reflection (rough surface)

- Specular reflectance (smooth surface)


Scattering
Scattering

(DIFFUSE)




Atmosphere effect on satellite image
Atmosphere Effect on Satellite Image

With atmosphere

No atmosphere


Atmospheric gases
Atmospheric Gases

Nitrogen (N2) - 78%, Oxygen (O2) - 21%, Carbon Dioxide (CO2) - 0.03 %, plus other miscellaneous gases (e.g., H2O).







Rules 1
Rules - 1

Rules govern the interaction between energy and the atmospheric media:

1. Since there is an indirect relationship between the energy of the photon and the wavelength, less electronic influence on the atmospheric particles is expecting in long wavelengths.

Ep= h*c/ 


Rules 2
Rules - 2

2. The longer the wavelength, the lesser statistical probability for a contact between the radiation and the atmospheric particles.


Scattering1
Scattering

Scattering: random re-direction of the radiation ray from parallel orbit to to an omni-direction orbit.



ScatteringTypes

Scattering Types

1. Selective scattering

- Rayleigh scattering

- Mie scattering

2. Non-selective scattering


Selective rayleigh scattering
Selective: Rayleigh Scattering

Partical size << 

Type of particles: gases, atmospheric molecules

Scattering intensity

Mostly affects blue light


A clear blue sky
AClear Blue Sky







UV/Skylight Filter

No Filter

Skylight Filter





Selective mie scattering
Selective: Mie Scattering

to

Partical size  

Mean diameter 0.1 to 10m

Type of particles: dust, smoke, soot, volcanic ash, water vapor, polen

Scattering intensity

Mostly affects red light


Mie scattering air pollution
Mie Scattering – Air Pollution

Haifa, Israel, November 2004



Mie Scattering – Volcanic Eruption

Mt. Pinatubo stratospheric Aerosol layer as seen from Space Shuttle STS-43 (August 1991). The stratospheric aerosol layer forming two distinct strata is clearly visible approximately 10 kilometers above the cloud tops.



Mie scattering haze episode
Mie Scattering – Haze Episode

Stead, Nevada, April 28, 1998


Nonselective scattering
Nonselective Scattering

Partical size >> 

Type of particles: water droplets, crystal ice.

Affects all wavelength equally

Independent of wavelength 0