Remote Sensing Electromagnetic Radiation

Remote SensingRemote Sensing

ElectromagneticElectromagnetic RadiationRadiation

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

Remote Sensing DefinitionRemote Sensing Definition

► ScienceScience and and artart of obtaining information of obtaining information about an object, area, or phenomenon about an object, area, or phenomenon through the analysis of data acquired by a through the analysis of data acquired by a device that is not in contact with object, device that is not in contact with object, area, or phenomenon. area, or phenomenon.

Remote Sensing ProcessesRemote Sensing Processes

► Data acquisition Data 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

Remote Sensing Processes ..Remote Sensing Processes ..

Remote Sensing Processes ..Remote Sensing Processes ..

► Data analysis: Data analysis:         - data processing         - data processing         - compilation         - compilation         - application        - application

► ““DIKI”DIKI”

datadata

informationinformation

knowledgeknowledge

intelligenceintelligence

Electronic RadiationElectronic Radiation

► The sun produces a full spectrum of The sun produces a full spectrum of electromagnetic radiation electromagnetic radiation

http://csep10.phys.utk.edu/astr162/lect/light/spectrum.html

http://kr.blog.yahoo.com/bmw26z/2188

Two Components of EM Two Components of EM Radiation Radiation

► Electrical field (E): varies in magnitude in a Electrical field (E): varies in magnitude in a direction perpendicular to the direction of direction perpendicular to the direction of propagation propagation

►   Magnetic field (M): at right angle to the Magnetic field (M): at right angle to the electrical field, is propagated in phase with electrical field, is propagated in phase with the electrical field the electrical field

Components of EM RadiationComponents of EM Radiation

v

Three Properties of EM Three Properties of EM Energy Energy

► Wavelength (Wavelength () ) ► Frequency (Frequency ())► AmplitudeAmplitude

Wavelength (Wavelength () )

► The distance from one wave crest to the The distance from one wave crest to the next next

► Measurement units: micrometer (Measurement units: micrometer (m) m)  1m = 1,000 mm, 1mm = 1,000microm 1m = 1,000 mm, 1mm = 1,000microm

Frequency (Frequency ())

► The number of crests passing a fixed point The 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)

AmplitudeAmplitude

► The height of each peakThe height of each peak► Measured as watts per square meter Measured as watts per square meter

(energy level) (energy level)

Three PropertiesThree Properties

► Among the three properties, wavelength is Among the three properties, wavelength is the most commonly used in the field of the most commonly used in the field of remote sensing remote sensing

Three Properties ..Three Properties ..

Speed of EMSpeed of EM

► The speed of EM energy  c  The speed of EM energy  c  300,000km/second,   c = 300,000km/second,   c =

andandare inversely relatedare inversely related

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.htmlhttp://imagers.gsfc.nasa.gov/ems/ems.html

Major Divisions of EM Major Divisions of EM SpectrumSpectrum

► 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

Major Divisions of EM Major Divisions of EM SpectrumSpectrum

► 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 earth emitted from the earth ► Microwave spectrum: 1mm - 1mMicrowave spectrum: 1mm - 1m

The Dual Nature of Light The Dual Nature of Light (Newton) (Newton)

► Light is formed by a stream of quanta Light is formed by a stream of quanta (photons) that travels in straight line. The (photons) that travels in straight line. The size of each quantum is directly proportional size of each quantum is directly proportional to the frequency of the energy's radiation to the frequency of the energy's radiation                     Q                    Qhh

► The quantum model best explains the The quantum model best explains the photoelectric effect photoelectric effect

The Dual Nature of Light The 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 The wave model best explains the refraction and diffraction refraction and diffraction

ReadingsReadings

► Chapter 1Chapter 1