L1 njs

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L1 njs

  1. 1. Remote SensingRemote Sensing ElectromagneticElectromagnetic RadiationRadiation
  2. 2. Remote Sensing DefinitionRemote Sensing Definition "I want to know how God created this world. I am not interested in this or that phenomenon, in the spectrum of this or that element. I want to know His thoughts; -the rest are details.“ Albert Einstein
  3. 3. Remote Sensing DefinitionRemote Sensing Definition ► ScienceScience andand artart of obtaining information about anof obtaining information about an object, area, or phenomenon through the analysisobject, area, or phenomenon through the analysis of data acquired by a device that is not in contactof data acquired by a device that is not in contact with object, area, or phenomenon.with object, area, or phenomenon.
  4. 4. Remote Sensing ProcessesRemote Sensing Processes ► Data acquisitionData acquisition         - energy sources        - energy sources         - energy through the atmosphere        - energy through the atmosphere         - interaction with surface features        - interaction with surface features         - retransmission        - retransmission         - sensor systems        - sensor systems         - data        - data - interpretation and analysis- interpretation and analysis
  5. 5. Remote Sensing Processes ..Remote Sensing Processes ..
  6. 6. Remote Sensing Processes ..Remote Sensing Processes .. ► Data analysis:Data analysis:         - data processing        - data processing         - compilation        - compilation         - application        - application ► ““DIKI”DIKI” datadata informationinformation knowledgeknowledge intelligenceintelligence
  7. 7. Electronic RadiationElectronic Radiation ► The sun produces a full spectrum ofThe sun produces a full spectrum of electromagnetic radiationelectromagnetic radiation http://csep10.phys.utk.edu/astr162/lect/light/spectrum.html http://kr.blog.yahoo.com/bmw26z/2188
  8. 8. Two Components of EMTwo Components of EM RadiationRadiation ► Electrical field (E): varies in magnitude in aElectrical field (E): varies in magnitude in a direction perpendicular to the direction ofdirection perpendicular to the direction of propagationpropagation ►   Magnetic field (M): at right angle to the electricalMagnetic field (M): at right angle to the electrical field, is propagated in phase with the electricalfield, is propagated in phase with the electrical fieldfield
  9. 9. Components of EM RadiationComponents of EM Radiation v
  10. 10. Three Properties of EM EnergyThree Properties of EM Energy ► Wavelength (Wavelength (λλ)) ► Frequency (Frequency (νν)) ► AmplitudeAmplitude
  11. 11. Wavelength (Wavelength (λλ)) ► The distance from one wave crest to the nextThe distance from one wave crest to the next ► Measurement units: micrometer (Measurement units: micrometer (µµm)m)  1m = 1,000 mm, 1mm = 1,000microm 1m = 1,000 mm, 1mm = 1,000microm λ
  12. 12. Frequency (Frequency (νν)) ► The number of crests passing a fixed pointThe number of crests passing a fixed point  in a given period of time in a given period of time ► Measure units: hertz (cycle per second)Measure units: hertz (cycle per second) ν
  13. 13. AmplitudeAmplitude ► The height of each peakThe height of each peak ► Measured as watts per square meter (energyMeasured as watts per square meter (energy level)level)
  14. 14. Three PropertiesThree Properties ► Among the three properties, wavelength is theAmong the three properties, wavelength is the most commonly used in the field of remotemost commonly used in the field of remote sensingsensing
  15. 15. Speed of EMSpeed of EM ► The speed of EM energy  c  300,000km/second,  The speed of EM energy  c  300,000km/second,   c =c = νλνλ λλ andand νν are inversely relatedare inversely related
  16. 16. Electromagnetic SpectrumElectromagnetic Spectrum ► Spectrum of electromagnetic radiationSpectrum of electromagnetic radiation ► Major divisions of EM spectrumMajor divisions of EM spectrum http://csep10.phys.utk.edu/astr162/lect/light/spectrum.html http://imagers.gsfc.nasa.gov/ems/ems.html
  17. 17. Major Divisions of EM SpectrumMajor Divisions of EM Spectrum ► Ultraviolet spectrum: 0.3 - 0.38micromUltraviolet spectrum: 0.3 - 0.38microm ►   Visible spectrum:Visible spectrum:         - blue  0.4 - 0.5microm        - blue  0.4 - 0.5microm         - green 0.5 - 0.6microm        - green 0.5 - 0.6microm         - red   0.6 - 0.72microm        - red   0.6 - 0.72microm ► 1m = 1,000mm = 1,000,000 micrometer1m = 1,000mm = 1,000,000 micrometer
  18. 18. Major Divisions of EM SpectrumMajor Divisions of EM Spectrum ► Infrared spectrum:Infrared spectrum:         - near infrared: 0.72 - 1.3microm        - near infrared: 0.72 - 1.3microm         - mid infrared:  1.30 - 3.0microm        - mid infrared:  1.30 - 3.0microm         - far infrared:  7.00 - 15microm,        - far infrared:  7.00 - 15microm, emitted from the earthemitted from the earth ► Microwave spectrum: 1mm - 1mMicrowave spectrum: 1mm - 1m
  19. 19. The Dual Nature of Light (Newton)The Dual Nature of Light (Newton) ► Light is formed by a stream of quanta (photons)Light is formed by a stream of quanta (photons) that travels in straight line. The size of eachthat travels in straight line. The size of each quantum is directly proportional to the frequency ofquantum is directly proportional to the frequency of the energy's radiationthe energy's radiation                     Q                    Q == hhνν ► The quantum model best explains theThe quantum model best explains the photoelectric effectphotoelectric effect
  20. 20. The Dual Nature of LightThe Dual Nature of Light ► EM energy propagates as a series of wavesEM energy propagates as a series of waves ► The wave model best explains the refraction andThe wave model best explains the refraction and diffractiondiffraction

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