1. Lesson 7: Remote Sensing Dr Andrew Ketsdever MAE 5595

2. Outline Electromagnetic Radiation Blackbody Radiation Atmospheric Windows Instrument Parameters Remote Sensing Architectures

3. EM Radiation Photon wavelength, frequency and energy h = 6.626 x 10 -34 J sec

4. EM Radiation Communications Microwaves: 1 mm to 1 m wavelength. The microwaves are further divided into different frequency (wavelength) bands: (1 GHz = 10 9 Hz) –P band: 0.3 - 1 GHz (30 - 100 cm) –L band: 1 - 2 GHz (15 - 30 cm) –S band: 2 - 4 GHz (7.5 - 15 cm) –C band: 4 - 8 GHz (3.8 - 7.5 cm) –X band: 8 - 12.5 GHz (2.4 - 3.8 cm) –Ku band: 12.5 - 18 GHz (1.7 - 2.4 cm) –K band: 18 - 26.5 GHz (1.1 - 1.7 cm) –Ka band: 26.5 - 40 GHz (0.75 - 1.1 cm) –V band: 50 – 75 GHz –W band: 75 – 111 GHz

5. EM Radiation Heat energy is the KE of random motion of the particles in matter Temperature is the measure of heat energy concentrated in a substance Random motion results in COLLISIONS COLLISIONS cause changes in the internal energy of the molecules Internal energy modes relax to ground state by giving off photons (EM Radiation)

6. Blackbody Radiation An ideal thermal emitter –Transforms heat energy into radiant energy at the maximum rate allowed (Thermodynamics) –Any real material at the same temperature can not emit at a rate in excess of a blackbody An ideal thermal absorber Planck’s formula C 1 = 3.74 x 10 -16 Wm 2 = 2  hc 2 C 2 = 1.44 x 10 -2 mK = hc/k

7. Blackbody Radiation Wien’s Displacement Law –Defines wavelength in a blackbody at which the maximum energy is emitted

8. Blackbody Radiation Stefan-Boltzmann Law –Relates the power emitted by a body to that body’s temperature  = 5.669 x 10 -8 Wm -2 K -4

9. Other Than Blackbody Radiation Emissivity –Ratio of the spectral energy radiated by a material to that of a blackbody at the same temperature –Can depend on Wavelength Temperature Phase (solid/liquid)

10. Atmospheric Windows

13. Atmospheric Window M13 Observations Rotational Transitions in CO

14. Window Transmission Glass Quartz Sapphire

15. Instrument Parameters Telescopes: Microwave, Radio, IR, Vis, UV, XRay, Gamma Ray

16. Instrument Parameters f – focal length h – altitude r d – radius of detector array R g – ½ Swath Width

17. Instrument Parameters Focal Length Refractive SystemReflective System

18. Instrument Parameters F-Stop or F-Number D - Aperture

19. Instrument Parameters A telescope's spatial (or angular) resolution refers to how well it can distinguish between two objects in space which are separated by a small angular distance. The closer two objects can be while still seen as two separate objects, the higher the spatial resolution of the telescope. The spatial resolution of a telescope affects how well details can be seen in an image. –A telescope with higher spatial resolution creates clearer and more detailed images.

20. Instrument Parameters Diffraction Limited Resolution –Rayleigh diffraction criteria –Angular distance from maximum brightness at the center of the image to the first dark interference ring h can be replaced by slant range for off Nadir obs.

21. Instrument Parameters Aberration Coma Stigmatism

22. Instrument Parameters

24. Silicon Imager Spectral Response

25. Instrument Parameters IR Detectors

27. Remote Sensing Architectures Global Ocean Temperatures

28. Remote Sensing Architectures Mie scattering (small particles) Rayleigh Scattering (large particles) Passive Active

29. Remote Sensing Architectures Cosmic Background Explorer SPOTMars Reconnaissance Orbiter What is the driver for the remote sensing architecture?

30. Remote Sensing Architectures Landsat 7 a panchromatic band with 15m spatial resolution on-board, full aperture, 5% absolute radiometric calibration a thermal IR channel with 60m spatial resolution an on-board data recorder

31. Remote Sensing Architectures Chicago Baghdad

32. Remote Sensing Architectures

33. Remote Sensing Architecture

34. Remote Sensing Architectures

35. Diffuse – Rough Surface Specular – Smooth Surface Maxwell Model

36. Remote Sensing Architectures

37. Space Radar –Mauna Loa Volcano Rift Zones (Orange) Smooth Lava Flows (Red) –Pahoehoe Flows Rough Lava Flows (Yellow/White) –A’a Flows –Obtained by sensing different Radar bands

38. Space Radar Systems

39. Remote Sensing Architectures

49. LIDAR –Light Detection and Ranging

50. Remote Sensing Architectures

51. Pushbroom Sensor