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2. 2 Definition 1 – Remote sensing is the acquiring of information about an object or scene without touching it through using electromagnetic energy a. RS deals with systems whose data can be used to recreate images b. RS deals with detection of the atmosphere, oceans, or land surface

3. 3

5. Wave Theory Speed of light c = 3*10 8 m/sec Wavelength = Frequency= v c = *v v = c/ = c/v

6. M =  T 4 The amount of EM radiation (M) emitted from a body in Watts m -2 can be calculated as The wavelength with the highest level of emitted radiation ( max ) for an object of temperature T can be calculated as max = k / T

7. Types of thermal energy transfer Models of EM radiation/energy Particle Model Photon absorption, excitation, de-excitation Wave Model Characteristics of EM waves Polarization, speed of light, wavelength, frequency Laws governing EM radiation Stephan-Boltzman Law Planck’s Formula Wien Displacement Law Remote sensing in the visible and reflected infrared region of the EM spectrum Maximum Solar Output Wavelengths λ Examples of Visible & RIR λ Images Basic Interactions of EM energy & the earths surface Descriptors of EM radiation Radiant flux Radiant flux density – irradiance and exitance Radiation budget equation Reflection Absorption Transmission Remote Detection of Exitance Radiance 7

8. 8 Wavelength region for VI/ reflected IR remote sensing is between 0.4 and 2.6  m Visible λ Reflected near and SW infrared Figure 1 Reflected IR λ

9. max = 2898/5880 = 0.49  m max = 9.7  m

10. 92%

12. Types of thermal energy transfer Models of EM radiation/energy Particle Model Photon absorption, excitation, de-excitation Wave Model Characteristics of EM waves Polarization, speed of light, wavelength, frequency Laws governing EM radiation Stephan-Boltzman Law Planck’s Formula Wien Displacement Law Remote sensing in the visible and reflected infrared region of the EM spectrum Maximum Solar Output Wavelengths λ Examples of Visible & RIR λ Images Basic Interactions of EM energy & the earths surface Descriptors of EM radiation Radiant flux Radiant flux density – irradiance and exitance Radiation budget equation Reflection Absorption Transmission Remote Detection of Exitance Radiance 12

13. 0.7 to 1.3  m – Near infrared 1.3 to 2.8  m – Reflected Middle or Shortwave (SW) IR region 13

14. True Color False Color

16. Columbia River Mt. St. Helens Mt. Adams

17. Columbia River Olympic Pen. Yellowstone N.P. Mt. St. Helens

19. Coral Reefs Bahamas

23. Types of thermal energy transfer Models of EM radiation/energy Particle Model Photon absorption, excitation, de-excitation Wave Model Characteristics of EM waves Polarization, speed of light, wavelength, frequency Laws governing EM radiation Stephan-Boltzman Law Planck’s Formula Wien Displacement Law Remote sensing in the visible and reflected infrared region of the EM spectrum Maximum Solar Output Wavelengths λ Examples of Visible & RIR λ Images Basic Interactions of EM energy & the earths surface Descriptors of EM radiation Radiant flux Radiant flux density – irradiance and exitance Radiation budget equation Reflection Absorption Transmission Remote Detection of Exitance Radiance 23

24. 24 1. Sun is EM Energy Source 2. Energy emitted from sun based on Stephan/Boltzmann Law, Planck’s formula, and Wein Displacement Law 3. EM Energy interacts with the atmosphere 4. EM energy interacts with the Earth’s Surface VIS/NIR Satellite EM energy 6. EM energy detected by a remote sensing system 5. EM Energy interacts with the atmosphere

25. Types of thermal energy transfer Models of EM radiation/energy Particle Model Photon absorption, excitation, de-excitation Wave Model Characteristics of EM waves Polarization, speed of light, wavelength, frequency Laws governing EM radiation Stephan-Boltzman Law Planck’s Formula Wien Displacement Law Remote sensing in the visible and reflected infrared region of the EM spectrum Maximum Solar Output Wavelengths λ Examples of Visible & RIR λ Images Basic Interactions of EM energy & the earths surface Descriptors of EM radiation Radiant flux Radiant flux density – irradiance and exitance Radiation budget equation Reflection Absorption Transmission Remote Detection of Exitance Radiance 25

26. The fundamental unit to measure electromagnetic radiation is radiant flux -   is defined as the amount of energy that passes into, through, or off of a surface per unit time Radiant flux (  ) is measured in Watts (W) 26

27. Newton - force required to cause the mass of one kilogram to accelerate at a rate of one meter per second squared Joule - the amount of energy exerted when a force of one newton is applied over a displacement of one meter Watt – one joule / second 27

28. 28  Radiant flux density is simply the amount of radiant flux per unit area Radiant flux density represents the amount of EM energy coming from the area represented by a pixel Radiant flux density =  /area

29. 29  Irradiance is the radiant flux energy that strikes a surface Exitance is the radiant flux density coming from a surface

30. 30 Irradiance is the amount of incident radiant flux per unit area to strike a plane surface in Watts/square meter (W m –2 ) Fig 2-20 in Jensen I

31. 31 Exitance is the amount of radiant flux per unit area leaving a plane surface in Watts per square meter (W m –2 ) Fig 2-20 in Jensen

32. Types of thermal energy transfer Models of EM radiation/energy Particle Model Photon absorption, excitation, de-excitation Wave Model Characteristics of EM waves Polarization, speed of light, wavelength, frequency Laws governing EM radiation Stephan-Boltzman Law Planck’s Formula Wien Displacement Law Remote sensing in the visible and reflected infrared region of the EM spectrum Maximum Solar Output Wavelengths λ Examples of Visible & RIR λ Images Basic Interactions of EM energy & the earths surface Descriptors of EM radiation Radiant flux Radiant flux density – irradiance and exitance Radiation budget equation Reflection Absorption Transmission Remote Detection of Exitance Radiance 32

33. Three things can happen to incident EM energy [  i ] when it interacts with a feature 1. Reflected 2. Absorbed 3. Transmitted 33 ii The degree to which EM energy is reflected, transmitted, and absorbed is dependent on the wavelength of the EM energy & the characteristics of the material the EM energy is interacting with

34. Reflectance (r) is the ratio of incident EM radiation that is directly reflected from a surface of an object: r =  r /  i Absorption (  ) is the ratio of incident EM that is absorbed by the object:  =  a /  i Transmittance (  ) is the ratio of incident EM radiation that is transmitted through an object:  =  t /  i 34

40.  i (λ)=  r (λ)+  t (λ) +  a (λ)  i (λ)= Incident Energy  r (λ)= Reflected Energy  a (λ)= Absorbed Energy  t (λ)= Transmitted Energy

41.  i =  r +  t +  a  r is the amount of energy reflected from the surface  a is the amount of energy absorbed by the surface  t is the amount of energy transmitted through the surface 41

42. Types of thermal energy transfer Models of EM radiation/energy Particle Model Photon absorption, excitation, de-excitation Wave Model Characteristics of EM waves Polarization, speed of light, wavelength, frequency Laws governing EM radiation Stephan-Boltzman Law Planck’s Formula Wien Displacement Law Remote sensing in the visible and reflected infrared region of the EM spectrum Maximum Solar Output Wavelengths λ Examples of Visible & RIR λ Images Basic Interactions of EM energy & the earths surface Descriptors of EM radiation Radiant flux Radiant flux density – irradiance and exitance Radiation budget equation Reflection Absorption Transmission Remote Detection of Exitance Radiance 42

43. 43 VIS/RIR Remote Sensor For a VIS/RIR remote sensing system, the surface characteristic being detected is the result of reflectance from the earth’s surface The sensors only detect reflected EM radiation from a certain direction and in certain wavelength regions

44. 44 In remote sensing, we are not interested in all exitance, but only that exitance in the direction of the satellite system Because of diffuse scattering, there is exitance in all directions from a surface

45. 45 θ – Sensor viewing angle Area as seen by the sensor (projected area) = A cos θ Satellite Radiometer A = area on ground being sensed

46. Flux from a surface is actually being emitted or reflected in all directions equally, i.e., it is being distributed into a hemisphere The radiometer intercepts a fraction of the exitance from a surface, this fraction is defined by the solid angle, Ω, of the sensing system, which can defined by the area of the detector surface (a) and the distance to the target area (d) Ω = a/d d a

47. Before Mt. Pinatubo Eruption After Mt. Pinatubo Eruption

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